diff --git a/libs/api-bot/src/Network/Wire/Bot/Assert.hs b/libs/api-bot/src/Network/Wire/Bot/Assert.hs
index 138c2fd4ab5..ed40c15e955 100644
--- a/libs/api-bot/src/Network/Wire/Bot/Assert.hs
+++ b/libs/api-bot/src/Network/Wire/Bot/Assert.hs
@@ -63,8 +63,8 @@ awaitOtrMessage ::
   m (Maybe (ConvEvent OtrMessage))
 awaitOtrMessage c (from, fc) (to, tc) =
   awaitEvent to TConvOtrMessageAdd assertion >>= \case
-    Just (EOtrMessage m) -> return (Just m)
-    _ -> return Nothing
+    Just (EOtrMessage m) -> pure (Just m)
+    _ -> pure Nothing
   where
     assertion (EOtrMessage evt) =
       let e = convEvtData evt
@@ -83,7 +83,7 @@ assertMembersJoined ::
   -- | Users who have (presumably) joined
   Maybe (ConvEvent SimpleMembers) ->
   m ()
-assertMembersJoined _ Nothing = return ()
+assertMembersJoined _ Nothing = pure ()
 assertMembersJoined bs (Just e) = forM_ bs $ \b ->
   assertEvent b TConvMemberJoin memAdd
   where
@@ -99,7 +99,7 @@ assertMembersLeft ::
   -- | Users who have (presumably) left
   Maybe (ConvEvent UserIdList) ->
   m ()
-assertMembersLeft _ Nothing = return ()
+assertMembersLeft _ Nothing = pure ()
 assertMembersLeft bs (Just e) = forM_ bs $ \b ->
   assertEvent b TConvMemberLeave memRem
   where
diff --git a/libs/api-bot/src/Network/Wire/Bot/Cache.hs b/libs/api-bot/src/Network/Wire/Bot/Cache.hs
index 612a7c9eb17..1a8b41d2cd5 100644
--- a/libs/api-bot/src/Network/Wire/Bot/Cache.hs
+++ b/libs/api-bot/src/Network/Wire/Bot/Cache.hs
@@ -58,7 +58,7 @@ fromFile logger gen domain path = do
   triples <- map (Text.splitOn ",") . Text.lines <$> Text.readFile path
   shuffled <- V.toList <$> uniformShuffle (V.fromList triples) gen
   c <- newIORef =<< foldM (toUser logger domain) [] shuffled
-  return (Cache c)
+  pure (Cache c)
 
 empty :: IO Cache
 empty = Cache <$> newIORef []
@@ -82,7 +82,7 @@ toUser _ domain acc [i, e, p] = do
   let ie = error "Cache.toUser: invalid email"
   let ui = fromMaybe iu . fromByteString . encodeUtf8 . Text.toStrict . Text.strip $ i
   let em = fromMaybe ie . parseEmail . Text.toStrict . Text.strip $ e
-  return . (: acc) $
+  pure . (: acc) $
     CachedUser
       pw
       User
@@ -103,4 +103,4 @@ toUser _ domain acc [i, e, p] = do
         }
 toUser g _ acc entry = do
   warn g $ msg (val "invalid entry: " +++ show entry)
-  return acc
+  pure acc
diff --git a/libs/api-bot/src/Network/Wire/Bot/Clients.hs b/libs/api-bot/src/Network/Wire/Bot/Clients.hs
index 707b02ce90a..80c22247d2b 100644
--- a/libs/api-bot/src/Network/Wire/Bot/Clients.hs
+++ b/libs/api-bot/src/Network/Wire/Bot/Clients.hs
@@ -57,7 +57,7 @@ addMembers self c uu =
 -- TODO: Move / inline to Network.Wire.Bot.Crypto and remove this module
 foldSessions :: MonadIO m => Clients -> ConvId -> a -> (UserId -> ClientId -> Session -> a -> m a) -> m a
 foldSessions self c a f =
-  foldrM fun a =<< Map.findWithDefault Set.empty c <$> liftIO (readTVarIO (members self))
+  foldrM fun a . Map.findWithDefault Set.empty c =<< liftIO (readTVarIO (members self))
   where
     fun u acc1 = do
       cm <- Map.findWithDefault Map.empty u . clients <$> liftIO (readTVarIO (sessions self))
@@ -66,4 +66,4 @@ foldSessions self c a f =
 lookupSession :: MonadIO m => Clients -> UserId -> ClientId -> m (Maybe Session)
 lookupSession self u d = do
   s <- liftIO $ readTVarIO (sessions self)
-  return $ Map.lookup u (clients s) >>= Map.lookup d
+  pure $ Map.lookup u (clients s) >>= Map.lookup d
diff --git a/libs/api-bot/src/Network/Wire/Bot/Crypto.hs b/libs/api-bot/src/Network/Wire/Bot/Crypto.hs
index 3e7ca8b526b..84e037529b5 100644
--- a/libs/api-bot/src/Network/Wire/Bot/Crypto.hs
+++ b/libs/api-bot/src/Network/Wire/Bot/Crypto.hs
@@ -95,7 +95,7 @@ clientInitSession cl uid = do
       k <- decodePrekey c
       let i = mkSID uid (prekeyClient c)
       s <- liftIO $ unwrap =<< CBox.sessionFromPrekey b i k
-      return (prekeyClient c, s)
+      pure (prekeyClient c, s)
 
 -- | Initialise an OTR session between the given 'BotClient' and the sender of
 -- the given OTR message.
@@ -116,12 +116,12 @@ encrypt cl cnv val = fmap (OtrRecipients . UserClientMap)
   . foldSessions (botClientSessions cl) cnv Map.empty
   $ \u c s rcps ->
     if botClientId cl == c
-      then return rcps
+      then pure rcps
       else liftIO $ do
         ciphertext <- do
           bs <- CBox.encrypt s val >>= unwrap >>= CBox.copyBytes
-          return $! decodeUtf8 $! B64.encode bs
-        return $ Map.insertWith Map.union u (Map.singleton c ciphertext) rcps
+          pure $! decodeUtf8 $! B64.encode bs
+        pure $ Map.insertWith Map.union u (Map.singleton c ciphertext) rcps
 
 -- | Decrypt an OTR message received from a given user and client.
 decrypt :: BotClient -> UserId -> ClientId -> ByteString -> BotSession ByteString
@@ -172,7 +172,7 @@ encryptSymmetric clt (SymmetricKeys ekey mkey) msg = liftIO $ do
   iv <- randomBytes (botClientBox clt) 16
   let ciphertext = iv <> cbcEncrypt aes (aesIV iv) (padPKCS7 msg)
   let mac = hmac (toByteString' mkey) ciphertext :: HMAC SHA256
-  return $ convert mac <> ciphertext
+  pure $ convert mac <> ciphertext
 
 decryptSymmetric :: MonadIO m => BotClient -> SymmetricKeys -> Ciphertext -> m Plaintext
 decryptSymmetric _ (SymmetricKeys ekey mkey) msg = liftIO $ do
@@ -184,7 +184,7 @@ decryptSymmetric _ (SymmetricKeys ekey mkey) msg = liftIO $ do
     throwM $
       RequirementFailed "Bad MAC"
   let (iv, dat) = BS.splitAt 16 ciphertext
-  return $ unpadPKCS7 $ cbcDecrypt aes (aesIV iv) dat
+  pure $ unpadPKCS7 $ cbcDecrypt aes (aesIV iv) dat
 
 -----------------------------------------------------------------------------
 -- Helpers
diff --git a/libs/api-bot/src/Network/Wire/Bot/Crypto/Glue.hs b/libs/api-bot/src/Network/Wire/Bot/Crypto/Glue.hs
index 1905fe82b1e..c0eec265b01 100644
--- a/libs/api-bot/src/Network/Wire/Bot/Crypto/Glue.hs
+++ b/libs/api-bot/src/Network/Wire/Bot/Crypto/Glue.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE LambdaCase #-}
-
 -- This file is part of the Wire Server implementation.
 --
 -- Copyright (C) 2022 Wire Swiss GmbH <opensource@wire.com>
@@ -67,7 +65,7 @@ randomBytes :: MonadIO m => Box -> Word32 -> m ByteString
 randomBytes b n = liftIO $ CBox.randomBytes b n >>= unwrap >>= CBox.copyBytes
 
 unwrap :: (Show a, MonadThrow m) => CBox.Result a -> m a
-unwrap (CBox.Success a) = return a
+unwrap (CBox.Success a) = pure a
 unwrap other = throwM $ userError (show other)
 
 getBoxDir :: UserId -> Maybe Text -> IO FilePath
@@ -75,4 +73,4 @@ getBoxDir uid label = do
   tmp <- getTemporaryDirectory
   let usrDir = show (toUUID uid)
   let cltDir = maybe "" Text.unpack label
-  return $ tmp </> "wire-bot" </> usrDir </> cltDir
+  pure $ tmp </> "wire-bot" </> usrDir </> cltDir
diff --git a/libs/api-bot/src/Network/Wire/Bot/Email.hs b/libs/api-bot/src/Network/Wire/Bot/Email.hs
index 73406dea5be..2d5dada326a 100644
--- a/libs/api-bot/src/Network/Wire/Bot/Email.hs
+++ b/libs/api-bot/src/Network/Wire/Bot/Email.hs
@@ -78,7 +78,7 @@ instance Exception MailException
 loadMailboxConfig :: FilePath -> IO [Mailbox]
 loadMailboxConfig p = do
   cfg <- LB.readFile p
-  mbs <- either error return (eitherDecode' cfg) :: IO [MailboxSettings]
+  mbs <- either error pure (eitherDecode' cfg) :: IO [MailboxSettings]
   mapM newMailbox mbs
 
 newMailbox :: MailboxSettings -> IO Mailbox
@@ -88,7 +88,7 @@ newMailbox s@(MailboxSettings host usr pwd conns) =
     connect = do
       c <- connectIMAPSSLWithSettings host defaultSettingsIMAPSSL
       login c (show usr) pwd
-      return c
+      pure c
 
 -- | Awaits activation e-mail to arrive at a mailbox with
 -- the designated recipient address.
@@ -109,7 +109,7 @@ awaitActivationMail mbox folders from to = do
     let codeHdr = find ((== "x-zeta-code") . paramName) hdrs
     case liftM2 (,) keyHdr codeHdr of
       Just (k, c) ->
-        return $
+        pure $
           ( ActivationKey $ Ascii.unsafeFromText $ paramValue k,
             ActivationCode $ Ascii.unsafeFromText $ paramValue c
           )
@@ -132,7 +132,7 @@ awaitPasswordResetMail mbox folders from to = do
     let codeHdr = find ((== "x-zeta-code") . paramName) hdrs
     case liftM2 (,) keyHdr codeHdr of
       Just (k, c) ->
-        return $
+        pure $
           ( PasswordResetKey $ Ascii.unsafeFromText $ paramValue k,
             PasswordResetCode $ Ascii.unsafeFromText $ paramValue c
           )
@@ -153,7 +153,7 @@ awaitInvitationMail mbox folders from to = do
     let hdrs = mime_val_headers msg
     let invHdr = find ((== "x-zeta-code") . paramName) hdrs
     case invHdr of
-      Just i -> return . read . T.unpack $ paramValue i
+      Just i -> pure . read . T.unpack $ paramValue i
       Nothing -> throwIO MissingEmailHeaders
 
 awaitMail ::
@@ -176,7 +176,7 @@ awaitMail mbox folders from to purpose = go 0
       case msgs of
         [] | t >= timeout -> throwIO EmailTimeout
         [] -> threadDelay sleep >> go (t + sleep)
-        (m : ms) -> return (m :| ms)
+        (m : ms) -> pure (m :| ms)
 
 fetchMail ::
   Mailbox ->
@@ -192,7 +192,7 @@ fetchMail ::
 fetchMail mbox folders from to purpose = withResource (mailboxPool mbox) $ \c -> do
   msgIds <- concat <$> forM folders (searchMail c)
   msgs <- mapM (fetch c) msgIds
-  return $ map (parseMIMEMessage . T.decodeLatin1) msgs
+  pure $ map (parseMIMEMessage . T.decodeLatin1) msgs
   where
     searchMail c folder = do
       select c folder
diff --git a/libs/api-bot/src/Network/Wire/Bot/Monad.hs b/libs/api-bot/src/Network/Wire/Bot/Monad.hs
index 04dcd73c4fd..6e36bc8efb9 100644
--- a/libs/api-bot/src/Network/Wire/Bot/Monad.hs
+++ b/libs/api-bot/src/Network/Wire/Bot/Monad.hs
@@ -158,7 +158,7 @@ newBotNetEnv manager logger o = do
   gen <- MWC.createSystemRandom
   let domain = setBotNetFederationDomain o
   usr <- maybe Cache.empty (Cache.fromFile logger gen domain) (setBotNetUsersFile o)
-  mbx <- maybe (return []) loadMailboxConfig (setBotNetMailboxConfig o)
+  mbx <- maybe (pure []) loadMailboxConfig (setBotNetMailboxConfig o)
   met <- initMetrics
   let srv =
         Server
@@ -169,7 +169,7 @@ newBotNetEnv manager logger o = do
             serverSSL = setBotNetApiSSL o,
             serverManager = manager
           }
-  return
+  pure
     $! BotNetEnv
       { botNetGen = gen,
         botNetMailboxes = mbx,
@@ -192,7 +192,7 @@ initMetrics = do
   m <- Metrics.metrics
   forM_ counters $ \c -> Metrics.counterGet c m
   forM_ gauges $ \g -> Metrics.gaugeGet g m
-  return m
+  pure m
   where
     counters =
       Metrics.assertionsTotal :
@@ -403,7 +403,7 @@ addBotClient self cty label = do
   cid <- clientId <$> runBotSession self (registerClient nc)
   clt <- BotClient cid label box <$> liftIO Clients.empty
   liftIO . atomically $ modifyTVar' (botClients self) (clt :)
-  return clt
+  pure clt
 
 -- TODO: withBotClient :: MonadBotNet m => Bot -> ClientType -> Maybe Text -> (BotClient -> m a) -> m a
 
@@ -455,7 +455,7 @@ newBot tag = liftBotNet $ do
   bot <- mkBot tag user pw
   -- TODO: addBotClient?
   incrBotsCreatedNew
-  return bot
+  pure bot
 
 -- | Obtain a "cached" 'Bot' based on an existing user identity. The same
 -- bot will never be returned again by 'cachedBot'.
@@ -466,7 +466,7 @@ cachedBot t = liftBotNet $ do
   CachedUser p u <- BotNet (asks botNetUsers) >>= Cache.get
   bot <- mkBot t (tagged t u) p
   incrBotsCreatedCached
-  return bot
+  pure bot
 
 -- | Wait for the Bot's assertions to finish (through matching
 -- an event or through timeout) before killing it (see 'killBot').
@@ -551,7 +551,7 @@ whenAsserts ma = liftBotNet $ do
 -- | Wait for the Bot's assertion queue to become empty.
 awaitAssertions :: MonadBotNet m => Bot -> m ()
 awaitAssertions bot = whenAsserts $ do
-  n <- liftIO . atomically $ readTVar (botAssertCount bot)
+  n <- liftIO (readTVarIO (botAssertCount bot))
   unless (n <= 0) $ do
     liftIO $ threadDelay 1000000
     awaitAssertions bot
@@ -560,20 +560,20 @@ awaitAssertions bot = whenAsserts $ do
 -- enabled or not. If the requirement fails, a 'RequirementFailed' exception
 -- is thrown.
 require :: MonadThrow m => Bool -> Text -> m ()
-require True _ = return ()
+require True _ = pure ()
 require False m = throwM $ RequirementFailed m
 
 -- | Require a 'Maybe a' to be 'Just a', regardless of whether assertions are
 -- enabled or not. If it is 'Nothing' a 'RequirementFailed' exception is thrown.
 requireMaybe :: MonadThrow m => Maybe a -> Text -> m a
 requireMaybe Nothing m = throwM $ RequirementFailed m
-requireMaybe (Just a) _ = return a
+requireMaybe (Just a) _ = pure a
 
 -- | Require a 'Either e a' to be 'Right a', regardless of whether assertions are
 -- enabled or not. If it is 'Left e 'RequirementFailed' exception is thrown.
 requireRight :: (Show e, MonadThrow m) => Either e a -> m a
 requireRight (Left e) = throwM $ RequirementFailed (pack $ show e)
-requireRight (Right a) = return a
+requireRight (Right a) = pure a
 
 -- TODO: change argument order to match 'assertEqual' from tasty-hunit
 assertEqual :: (HasCallStack, MonadBotNet m, Show a, Eq a) => a -> a -> Text -> m ()
@@ -630,11 +630,11 @@ scheduleAssert bot typ f out = whenAsserts $ do
   r <- liftIO . atomically $ do
     n <- readTVar (botAssertCount bot)
     if n >= botMaxAsserts (botSettings bot)
-      then return False
+      then pure False
       else do
         writeTQueue (botAsserts bot) (EventAssertion typ t f out callStack)
         writeTVar (botAssertCount bot) (n + 1)
-        return True
+        pure True
   unless r . liftBotNet $ do
     incrAssertFailed
     runBotSession bot . log Error . msg $
@@ -675,13 +675,13 @@ try ma = do
     Left e -> do
       liftBotNet $ log Error . msg $ show e
       incrExceptionsTotal
-      return $ Left e
-    Right a -> return $ Right a
+      pure $ Left e
+    Right a -> pure $ Right a
   where
     handlers =
-      [ Handler $ \e -> return . Left $ BotNetFailure e,
-        Handler $ \e -> return . Left $ HttpFailure e,
-        Handler $ \e -> return . Left $ ClientFailure e
+      [ Handler $ \e -> pure . Left $ BotNetFailure e,
+        Handler $ \e -> pure . Left $ HttpFailure e,
+        Handler $ \e -> pure . Left $ ClientFailure e
       ]
 
 -------------------------------------------------------------------------------
@@ -692,7 +692,7 @@ mkBot tag user pw = do
   log Info $ botLogFields (userId user) tag . msg (val "Login")
   let ident = fromMaybe (error "No email") (userEmail user)
   let cred = PasswordLogin (LoginByEmail ident) pw Nothing Nothing
-  auth <- login cred >>= maybe (throwM LoginFailed) return
+  auth <- login cred >>= maybe (throwM LoginFailed) pure
   aref <- nextAuthRefresh auth
   env <- BotNet ask
   bot <-
@@ -715,7 +715,7 @@ mkBot tag user pw = do
     when (botNetAssert env) $
       writeIORef (botAssertThread bot) . Just =<< async (assert bot env)
   incrBotsAlive
-  return bot
+  pure bot
 
 connectPush :: Bot -> BotNetEnv -> IO (Async ())
 connectPush bot e = runBotNet e . runBotSession bot $ do
@@ -775,7 +775,7 @@ heartbeat bot e = forever $ do
             <> "\nAssertion was created at: "
             <> pack (prettyCallStack stack)
   -- Re-establish the push connection, if it died
-  push <- maybe (return Nothing) poll =<< readIORef (botPushThread bot)
+  push <- maybe (pure Nothing) poll =<< readIORef (botPushThread bot)
   case push of
     Just x -> do
       case x of
@@ -783,7 +783,7 @@ heartbeat bot e = forever $ do
         Right _ -> botLog l bot Warn $ msg $ val "Unexpected exit of push thread"
       a <- connectPush bot e
       writeIORef (botPushThread bot) (Just a)
-    Nothing -> return ()
+    Nothing -> pure ()
 
 assert :: Bot -> BotNetEnv -> IO a
 assert bot e = forever $ do
@@ -807,7 +807,7 @@ matchAssertion bot a@(EventAssertion _ _ f out _) = do
       modifyTVar' (botAssertCount bot) (subtract 1)
       incrEventsAckd bot (eventType ev)
     Nothing -> modifyTVar' (botBacklog bot) (a :)
-  return found
+  pure found
   where
     go (events, found) (et, ev)
       | isNothing found && f ev = (events, Just ev)
@@ -833,7 +833,7 @@ gcEvents bot now = do
   when (numDel > 0) $ do
     writeTVar (botEvents bot) (num - numDel, keep)
     mapM_ (incrEventsIgnd bot . eventType . snd) del
-  return $ fmap snd del
+  pure $ fmap snd del
 
 gcBacklog :: Bot -> UTCTime -> STM [EventAssertion]
 gcBacklog bot now = do
@@ -847,12 +847,12 @@ gcBacklog bot now = do
     forM_ del $ \(EventAssertion typ _ _ out _) -> do
       for_ out $ flip tryPutTMVar Nothing
       incrEventsMssd bot typ
-  return del
+  pure del
 
 nextAuthRefresh :: MonadIO m => Auth -> m UTCTime
 nextAuthRefresh (Auth _ tok) = liftIO $ do
   now <- getCurrentTime
-  return $ (fromInteger (expiresIn tok) - 60) `addUTCTime` now
+  pure $ (fromInteger (expiresIn tok) - 60) `addUTCTime` now
 
 -------------------------------------------------------------------------------
 
@@ -869,7 +869,7 @@ report t s = do
           f = showString (unpack t) . showString "-" . showString d $ ".bot"
        in writeReport (dir </> f) r
     Nothing -> printReport r
-  return r
+  pure r
 
 getMetrics :: MonadBotNet m => m Metrics
 getMetrics = liftBotNet . BotNet $ asks botNetMetrics
@@ -883,7 +883,7 @@ timed p ma = do
   m <- getMetrics
   let timeHisto = Metrics.deprecatedRequestDurationHistogram p
   liftIO $ Metrics.histoSubmit durationInMillis timeHisto m
-  return a
+  pure a
 
 incrAssertTotal :: MonadBotNet m => m ()
 incrAssertTotal = getMetrics >>= liftIO . Metrics.counterIncr Metrics.assertionsTotal
@@ -951,7 +951,7 @@ transferBotMetrics b =
       ackd <- readTVar $ botEventsAckd (botMetrics b)
       ignd <- readTVar $ botEventsIgnd (botMetrics b)
       mssd <- readTVar $ botEventsMssd (botMetrics b)
-      return [rcvd, ackd, ignd, mssd]
+      pure [rcvd, ackd, ignd, mssd]
     -- Update per event type counters
     let add (p, n) = Metrics.counterAdd n p m
     mapM_ add (concatMap HashMap.toList l)
@@ -981,7 +981,7 @@ randUser (Email loc dom) (BotTag tag) = do
   pwdUuid <- nextRandom
   let email = Email (loc <> "+" <> tag <> "-" <> pack (toString uuid)) dom
   let passw = PlainTextPassword (pack (toString pwdUuid))
-  return
+  pure
     ( NewUser
         { newUserDisplayName = Name (tag <> "-Wirebot-" <> pack (toString uuid)),
           newUserUUID = Nothing,
@@ -1005,7 +1005,7 @@ randMailbox :: BotNet Mailbox
 randMailbox = do
   e <- BotNet ask
   i <- liftIO $ MWC.uniformR (0, length (botNetMailboxes e) - 1) (botNetGen e)
-  return $ botNetMailboxes e !! i
+  pure $ botNetMailboxes e !! i
 
 tagged :: BotTag -> User -> User
 tagged t u = u {userDisplayName = Name $ unTag t <> "-" <> fromName (userDisplayName u)}
diff --git a/libs/api-bot/src/Network/Wire/Bot/Report.hs b/libs/api-bot/src/Network/Wire/Bot/Report.hs
index a729ad0cd9c..9a590260064 100644
--- a/libs/api-bot/src/Network/Wire/Bot/Report.hs
+++ b/libs/api-bot/src/Network/Wire/Bot/Report.hs
@@ -71,19 +71,19 @@ createReport :: MonadIO m => Text -> Metrics -> SectionS -> m Report
 createReport t m (SectionS (Endo f)) = do
   d <- liftIO getCurrentTime
   v <- liftIO $ foldM go mempty (concatMap sectionMetrics s)
-  return $! Report t d s v
+  pure $! Report t d s v
   where
     s = f []
     go (Data cs ls bs gs) metric = case metric of
       Counter _ p -> do
         v <- counterValue =<< counterGet p m
-        return $! Data (HashMap.insert p v cs) ls bs gs
+        pure $! Data (HashMap.insert p v cs) ls bs gs
       Gauge _ p -> do
         v <- gaugeValue =<< gaugeGet p m
-        return $! Data cs ls bs (HashMap.insert p v gs)
+        pure $! Data cs ls bs (HashMap.insert p v gs)
       Histogram _ p hi -> do
         v <- histoGet hi m >>= histoValue
-        return $! Data cs ls (HashMap.insert p v bs) gs
+        pure $! Data cs ls (HashMap.insert p v bs) gs
 
 -------------------------------------------------------------------------------
 
diff --git a/libs/api-bot/src/Network/Wire/Bot/Report/Text.hs b/libs/api-bot/src/Network/Wire/Bot/Report/Text.hs
index d12a59a30ba..17afb497862 100644
--- a/libs/api-bot/src/Network/Wire/Bot/Report/Text.hs
+++ b/libs/api-bot/src/Network/Wire/Bot/Report/Text.hs
@@ -60,8 +60,8 @@ formatReport pretty r =
       pp bold <> fromText (sectionName s) <> "\n" <> pp clear
         <> foldMap metric (sectionMetrics s)
         <> "\n"
-    metric (Counter l p) = single l . fromString . show $ (reportCounter r p)
-    metric (Gauge l p) = single l . fromString . show $ (reportGauge r p)
+    metric (Counter l p) = single l . fromString . show $ reportCounter r p
+    metric (Gauge l p) = single l . fromString . show $ reportGauge r p
     metric (Histogram l p _) = multi l $ sort $ Map.toList (reportBucket r p)
     single k v = "\t" <> fromText k <> ": " <> value v <> "\n"
     multi k v = "\t" <> subsection k <> "\n" <> foldMap pair v
diff --git a/libs/api-bot/src/Network/Wire/Bot/Settings.hs b/libs/api-bot/src/Network/Wire/Bot/Settings.hs
index 823adb2697b..15d0f447b90 100644
--- a/libs/api-bot/src/Network/Wire/Bot/Settings.hs
+++ b/libs/api-bot/src/Network/Wire/Bot/Settings.hs
@@ -147,7 +147,7 @@ usersFileOption =
         \ containing a list of ALREADY EXISTING users with the columns: \
         \ User-Id,Email,Password"
 
-usersFederationDomain :: Parser (Domain)
+usersFederationDomain :: Parser Domain
 usersFederationDomain =
   domainOption $
     long "users-federation-domain"
@@ -275,7 +275,7 @@ assertTimeoutOption =
 greater :: (Integral a, Show a) => a -> a -> ReadM a
 greater n a
   | a <= n = readerError ("must be > " ++ show n)
-  | otherwise = return a
+  | otherwise = pure a
 
 bsOption :: Mod OptionFields String -> Parser ByteString
 bsOption = fmap pack . strOption
diff --git a/libs/api-client/src/Network/Wire/Client/API/Asset.hs b/libs/api-client/src/Network/Wire/Client/API/Asset.hs
index 9fc48d83188..e68c7719472 100644
--- a/libs/api-client/src/Network/Wire/Client/API/Asset.hs
+++ b/libs/api-client/src/Network/Wire/Client/API/Asset.hs
@@ -69,8 +69,8 @@ getAsset :: MonadSession m => AssetKey -> Maybe AssetToken -> m (Maybe AssetData
 getAsset key tok = do
   rs <- sessionRequest req rsc consumeBody
   liftIO $ case statusCode rs of
-    200 -> maybe (unexpected rs "getAsset: missing body") (return . Just) (responseBody rs)
-    404 -> return Nothing
+    200 -> maybe (unexpected rs "getAsset: missing body") (pure . Just) (responseBody rs)
+    404 -> pure Nothing
     _ -> unexpected rs "getAsset: response code"
   where
     req =
diff --git a/libs/api-client/src/Network/Wire/Client/API/Auth.hs b/libs/api-client/src/Network/Wire/Client/API/Auth.hs
index 12c6c7816eb..aaaa54b6e47 100644
--- a/libs/api-client/src/Network/Wire/Client/API/Auth.hs
+++ b/libs/api-client/src/Network/Wire/Client/API/Auth.hs
@@ -110,17 +110,17 @@ tokenResponse ::
   IO (Maybe Auth)
 tokenResponse rq rs ck
   | statusCode rs == 200 = mkAuth
-  | statusCode rs == 403 = return Nothing
+  | statusCode rs == 403 = pure Nothing
   | otherwise = unexpected rs "tokenResponse: status code"
   where
     mkAuth = do
       cok <- mkCookie $ parseSetCookie <$> getHeader "Set-Cookie" rs
       tok <- responseJsonThrow (ParseError . pack) rs
-      return . Just $ Auth cok tok
-    mkCookie Nothing = maybe (unexpected rs "missing set-cookie") return ck
+      pure . Just $ Auth cok tok
+    mkCookie Nothing = maybe (unexpected rs "missing set-cookie") pure ck
     mkCookie (Just hdr) = do
       now <- getCurrentTime
       case generateCookie hdr rq now True of
-        Just cok | cookie_name cok == "zuid" -> return $ AuthCookie cok
+        Just cok | cookie_name cok == "zuid" -> pure $ AuthCookie cok
         Just (cookie_name -> cok) -> unexpected rs $ "unknown cookie: " <> T.decodeLatin1 cok
         Nothing -> unexpected rs "invalid cookie"
diff --git a/libs/api-client/src/Network/Wire/Client/API/Client.hs b/libs/api-client/src/Network/Wire/Client/API/Client.hs
index 4d436ce4798..ff41887026f 100644
--- a/libs/api-client/src/Network/Wire/Client/API/Client.hs
+++ b/libs/api-client/src/Network/Wire/Client/API/Client.hs
@@ -52,7 +52,7 @@ registerClient a = sessionRequest req rsc readBody
     rsc = status201 :| []
 
 removeClient :: MonadSession m => ClientId -> RmClient -> m ()
-removeClient cid r = sessionRequest req rsc (const $ return ())
+removeClient cid r = sessionRequest req rsc (const $ pure ())
   where
     req =
       method DELETE
@@ -73,7 +73,7 @@ getClients = sessionRequest req rsc readBody
     rsc = status200 :| []
 
 updateClient :: MonadSession m => ClientId -> UpdateClient -> m ()
-updateClient cid r = sessionRequest req rsc (const $ return ())
+updateClient cid r = sessionRequest req rsc (const $ pure ())
   where
     req =
       method PUT
diff --git a/libs/api-client/src/Network/Wire/Client/API/Conversation.hs b/libs/api-client/src/Network/Wire/Client/API/Conversation.hs
index b4a2cb47173..3dc4ace781d 100644
--- a/libs/api-client/src/Network/Wire/Client/API/Conversation.hs
+++ b/libs/api-client/src/Network/Wire/Client/API/Conversation.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE ViewPatterns #-}
 
 -- This file is part of the Wire Server implementation.
 --
@@ -72,7 +71,7 @@ addMembers cnv mems = do
   rs <- sessionRequest req rsc consumeBody
   case statusCode rs of
     200 -> Just <$> responseJsonThrow (ParseError . pack) rs
-    204 -> return Nothing
+    204 -> pure Nothing
     _ -> unexpected rs "addMembers: status code"
   where
     req =
@@ -90,7 +89,7 @@ removeMember cnv mem = do
   rs <- sessionRequest req rsc consumeBody
   case statusCode rs of
     200 -> Just <$> responseJsonThrow (ParseError . pack) rs
-    204 -> return Nothing
+    204 -> pure Nothing
     _ -> unexpected rs "removeMember: status code"
   where
     req =
@@ -102,7 +101,7 @@ removeMember cnv mem = do
 
 -- FUTUREWORK: probably should be 'Wire.API.Conversation.Member.MemberUpdate'.
 memberUpdate :: MonadSession m => ConvId -> MemberUpdateData -> m ()
-memberUpdate cnv updt = sessionRequest req rsc (const $ return ())
+memberUpdate cnv updt = sessionRequest req rsc (const $ pure ())
   where
     req =
       method PUT
@@ -117,7 +116,7 @@ getConv cnv = do
   rs <- sessionRequest req rsc consumeBody
   case statusCode rs of
     200 -> responseJsonThrow (ParseError . pack) rs
-    404 -> return Nothing
+    404 -> pure Nothing
     _ -> unexpected rs "getConv: status code"
   where
     req =
diff --git a/libs/api-client/src/Network/Wire/Client/API/Push.hs b/libs/api-client/src/Network/Wire/Client/API/Push.hs
index b74419fb168..cddd7be34c0 100644
--- a/libs/api-client/src/Network/Wire/Client/API/Push.hs
+++ b/libs/api-client/src/Network/Wire/Client/API/Push.hs
@@ -118,7 +118,7 @@ awaitNotifications f = do
               putMVar latch () >> consume l c
           `onException` tryPutMVar latch ()
     takeMVar latch
-    return worker
+    pure worker
   where
     params h p = ConnectionParams h p Nothing Nothing
     consume l c = forever (WS.receiveData c >>= forward l) `finally` close c
@@ -130,7 +130,7 @@ awaitNotifications f = do
         Right event -> f event
         Left e -> Log.err l $ Log.msg ("parse-event: " ++ e)
     readChunk c = (\x -> if C.null x then Nothing else Just x) <$> connectionGetChunk c
-    writeChunk c = maybe (return ()) (connectionPut c . L.toStrict)
+    writeChunk c = maybe (pure ()) (connectionPut c . L.toStrict)
 
 fetchNotifications ::
   (MonadSession m, MonadThrow m) =>
@@ -156,7 +156,7 @@ lastNotification = do
   rs <- sessionRequest req rsc consumeBody
   case statusCode rs of
     200 -> Just <$> responseJsonThrow (ParseError . pack) rs
-    404 -> return Nothing
+    404 -> pure Nothing
     _ -> unexpected rs "last: status code"
   where
     req =
@@ -279,7 +279,7 @@ instance FromJSON Event where
 instance FromJSON NotifId where
   parseJSON =
     withText "notification-id" $
-      maybe (fail "invalid uuid") (return . NotifId) . fromString . T.unpack
+      maybe (fail "invalid uuid") (pure . NotifId) . fromString . T.unpack
 
 instance FromJSON Notification where
   parseJSON = withObject "notification" $ \o ->
@@ -293,7 +293,7 @@ instance FromJSON a => FromJSON (ConvEvent a) where
       <*> o .: "data"
 
 instance FromJSON NoData where
-  parseJSON Null = return NoData
+  parseJSON Null = pure NoData
   parseJSON _ = fail "Unexpected event data. Expecting nothing/null."
 
 instance FromJSON UserInfo where
diff --git a/libs/api-client/src/Network/Wire/Client/API/User.hs b/libs/api-client/src/Network/Wire/Client/API/User.hs
index 7bb4f472e67..7013d48c70c 100644
--- a/libs/api-client/src/Network/Wire/Client/API/User.hs
+++ b/libs/api-client/src/Network/Wire/Client/API/User.hs
@@ -64,8 +64,8 @@ registerUser u = clientRequest req rsc readBody
 
 activateKey :: (MonadClient m, MonadUnliftIO m, MonadMask m) => ActivationKey -> ActivationCode -> m Bool
 activateKey (ActivationKey key) (ActivationCode code) = do
-  status <- clientRequest req rsc (return . statusCode)
-  return $ status /= 404
+  status <- clientRequest req rsc (pure . statusCode)
+  pure $ status /= 404
   where
     req =
       method GET
@@ -124,7 +124,7 @@ getConnection u = do
   rs <- sessionRequest req rsc consumeBody
   case statusCode rs of
     200 -> responseJsonThrow (ParseError . pack) rs
-    404 -> return Nothing
+    404 -> pure Nothing
     _ -> unexpected rs "getConnection: status code"
   where
     req =
diff --git a/libs/api-client/src/Network/Wire/Client/HTTP.hs b/libs/api-client/src/Network/Wire/Client/HTTP.hs
index 4e5090d0fa1..20a4b499bd7 100644
--- a/libs/api-client/src/Network/Wire/Client/HTTP.hs
+++ b/libs/api-client/src/Network/Wire/Client/HTTP.hs
@@ -80,7 +80,7 @@ clientRequest rq expected f = do
       [ const $
           Handler
             ( \(e :: ClientException) -> case e of
-                ErrorResponse c _ _ -> return (canRetry c)
+                ErrorResponse c _ _ -> pure (canRetry c)
                 x -> throwIO x
             ),
         const $ Handler (\(e :: SomeException) -> throwIO e)
@@ -123,6 +123,6 @@ mkErrorResponse rs = do
                 (eitherDecode bdy)
           )
           (responseBody r)
-  return $ case re of
+  pure $ case re of
     Left m -> ErrorResponse (statusCode rs) "N/A" m
     Right e -> ErrorResponse (code e) (label e) (message e)
diff --git a/libs/api-client/src/Network/Wire/Client/Session.hs b/libs/api-client/src/Network/Wire/Client/Session.hs
index 51aa5f0cad3..740a4c6ff9a 100644
--- a/libs/api-client/src/Network/Wire/Client/Session.hs
+++ b/libs/api-client/src/Network/Wire/Client/Session.hs
@@ -75,7 +75,7 @@ sessionRequest ::
   (Response BodyReader -> IO a) ->
   m a
 sessionRequest rq expected f =
-  either retry return
+  either retry pure
     =<< exec
       ( \rs ->
           if Bilge.statusCode rs == 401
diff --git a/libs/bilge/src/Bilge/Assert.hs b/libs/bilge/src/Bilge/Assert.hs
index 03393bd9bc3..71159fcd04f 100644
--- a/libs/bilge/src/Bilge/Assert.hs
+++ b/libs/bilge/src/Bilge/Assert.hs
@@ -90,7 +90,7 @@ io <!! aa = do
       title "Assertions failed:\n" :
       intersperse "\n" (map msg failures)
         ++ ["\n\nResponse was:\n\n" ++ show r]
-  return r
+  pure r
   where
     msg :: (Int, Maybe String) -> String
     msg (i, Just m) = printf "%2d: " i ++ err m
diff --git a/libs/bilge/src/Bilge/IO.hs b/libs/bilge/src/Bilge/IO.hs
index 16db8d84c9d..18ed2b5b65c 100644
--- a/libs/bilge/src/Bilge/IO.hs
+++ b/libs/bilge/src/Bilge/IO.hs
@@ -128,7 +128,7 @@ instance MonadIO m => MonadHttp (HttpT m) where
 trivialBodyReader :: ByteString -> IO BodyReader
 trivialBodyReader bodyBytes = do
   bodyVar <- newTVarIO bodyBytes
-  return $ mkBodyReader bodyVar
+  pure $ mkBodyReader bodyVar
   where
     mkBodyReader :: TVar ByteString -> BodyReader
     mkBodyReader bodyVar = do
@@ -270,7 +270,7 @@ http ::
   (Request -> Request) ->
   (Response BodyReader -> IO a) ->
   m a
-http r f h = handleRequestWithCont (f r) h
+http r f = handleRequestWithCont (f r)
 
 httpDebug ::
   (MonadIO m, MonadHttp m) =>
@@ -289,7 +289,7 @@ httpDebug debug r f h = do
     consumeBody >=> \rsp -> do
       if debug > Head
         then putStrLn (showResponse rsp)
-        else putStrLn (showResponse $ rsp {responseBody = ("" :: String)})
+        else putStrLn (showResponse $ rsp {responseBody = "" :: String})
       putStrLn "--"
       h rsp
 
@@ -300,4 +300,4 @@ consumeBody r = do
         if null chunks
           then Nothing
           else Just (LBS.fromChunks chunks)
-  return $ r {responseBody = bdy}
+  pure $ r {responseBody = bdy}
diff --git a/libs/bilge/src/Bilge/RPC.hs b/libs/bilge/src/Bilge/RPC.hs
index fbdf4bae7bd..34bd8d059b2 100644
--- a/libs/bilge/src/Bilge/RPC.hs
+++ b/libs/bilge/src/Bilge/RPC.hs
@@ -95,7 +95,7 @@ rpc' sys r f = do
   res <- try $ httpLbs rq id
   case res of
     Left x -> throwM $ RPCException sys rq x
-    Right x -> return x
+    Right x -> pure x
 
 rpcExceptionMsg :: RPCException -> Msg -> Msg
 rpcExceptionMsg (RPCException sys req ex) =
@@ -120,6 +120,6 @@ parseResponse ::
   (LText -> e) ->
   Response (Maybe LByteString) ->
   m a
-parseResponse f r = either throwM return $ do
+parseResponse f r = either throwM pure $ do
   b <- note (f "no response body") (responseBody r)
   fmapL (f . pack) (eitherDecode' b)
diff --git a/libs/bilge/src/Bilge/Request.hs b/libs/bilge/src/Bilge/Request.hs
index f7461d0523c..99d4acfc381 100644
--- a/libs/bilge/src/Bilge/Request.hs
+++ b/libs/bilge/src/Bilge/Request.hs
@@ -153,17 +153,15 @@ expectStatus :: (Int -> Bool) -> Request -> Request
 expectStatus property r = r {Rq.checkResponse = check}
   where
     check _ res
-      | property (HTTP.statusCode (Rq.responseStatus res)) = return ()
+      | property (HTTP.statusCode (Rq.responseStatus res)) = pure ()
       | otherwise = do
         some <- Lazy.toStrict <$> brReadSome (Rq.responseBody res) 1024
-        throwHttp $ Rq.StatusCodeException (const () <$> res) some
+        throwHttp $ Rq.StatusCodeException (() <$ res) some
 
 checkStatus :: (Status -> ResponseHeaders -> CookieJar -> Maybe SomeException) -> Request -> Request
 checkStatus f r = r {Rq.checkResponse = check}
   where
-    check _ res = case mayThrow res of
-      Nothing -> return ()
-      Just ex -> throwIO ex
+    check _ res = forM_ (mayThrow res) throwIO
     mayThrow res =
       f
         (Rq.responseStatus res)
@@ -244,4 +242,4 @@ extPort :: URI.URI -> Maybe Word16
 extPort u = do
   a <- u ^. URI.authorityL
   p <- a ^. URI.authorityPortL
-  return (fromIntegral (p ^. URI.portNumberL))
+  pure (fromIntegral (p ^. URI.portNumberL))
diff --git a/libs/bilge/src/Bilge/Response.hs b/libs/bilge/src/Bilge/Response.hs
index 22c1b755078..f8019c32f33 100644
--- a/libs/bilge/src/Bilge/Response.hs
+++ b/libs/bilge/src/Bilge/Response.hs
@@ -140,7 +140,7 @@ responseJsonUnsafeWithMsg ::
 responseJsonUnsafeWithMsg userErr = either err id . responseJsonEither
   where
     err parserErr =
-      error . intercalate " " $
+      error . unwords $
         ["responseJsonUnsafeWithMsg:"]
           <> [userErr | not $ null userErr]
           <> [parserErr]
diff --git a/libs/bilge/src/Bilge/Retry.hs b/libs/bilge/src/Bilge/Retry.hs
index 0b499b9c18d..01f2dc7ab01 100644
--- a/libs/bilge/src/Bilge/Retry.hs
+++ b/libs/bilge/src/Bilge/Retry.hs
@@ -26,12 +26,12 @@ import Network.HTTP.Client (HttpException (..), HttpExceptionContent (..), respo
 import Network.HTTP.Types
 
 httpHandlers :: Monad m => [a -> Handler m Bool]
-httpHandlers = [const . Handler $ return . canRetry]
+httpHandlers = [const . Handler $ pure . canRetry]
 
 rpcHandlers :: Monad m => [a -> Handler m Bool]
 rpcHandlers =
   [ const . Handler $ \(RPCException _ _ cause) ->
-      return $ maybe False canRetry (fromException cause)
+      pure $ maybe False canRetry (fromException cause)
   ]
 
 canRetry :: HttpException -> Bool
diff --git a/libs/brig-types/src/Brig/Types/Common.hs b/libs/brig-types/src/Brig/Types/Common.hs
index b92ec418674..a7a8b3a17a4 100644
--- a/libs/brig-types/src/Brig/Types/Common.hs
+++ b/libs/brig-types/src/Brig/Types/Common.hs
@@ -118,14 +118,14 @@ allPrefixes t = catMaybes $ parsePhonePrefix <$> Text.inits t
 instance FromJSON PhonePrefix where
   parseJSON = withText "PhonePrefix" $ \s ->
     case parsePhonePrefix s of
-      Just p -> return p
+      Just p -> pure p
       Nothing ->
         fail $
           "Invalid phone number prefix: [" ++ show s
             ++ "]. Expected format similar to E.164 (with 1-15 digits after the +)."
 
 instance FromByteString PhonePrefix where
-  parser = parser >>= maybe (fail "Invalid phone") return . parsePhonePrefix
+  parser = parser >>= maybe (fail "Invalid phone") pure . parsePhonePrefix
 
 instance ToByteString PhonePrefix where
   builder = builder . fromPhonePrefix
diff --git a/libs/brig-types/src/Brig/Types/Connection.hs b/libs/brig-types/src/Brig/Types/Connection.hs
index f9f24145fa0..eaac6f88edf 100644
--- a/libs/brig-types/src/Brig/Types/Connection.hs
+++ b/libs/brig-types/src/Brig/Types/Connection.hs
@@ -1,6 +1,4 @@
-{-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RecordWildCards #-}
 
 -- This file is part of the Wire Server implementation.
 --
diff --git a/libs/brig-types/src/Brig/Types/Instances.hs b/libs/brig-types/src/Brig/Types/Instances.hs
index c9e19c77970..de70e73e798 100644
--- a/libs/brig-types/src/Brig/Types/Instances.hs
+++ b/libs/brig-types/src/Brig/Types/Instances.hs
@@ -32,14 +32,14 @@ import Imports
 instance Cql PrekeyId where
   ctype = Tagged IntColumn
   toCql = CqlInt . fromIntegral . keyId
-  fromCql (CqlInt i) = return $ PrekeyId (fromIntegral i)
+  fromCql (CqlInt i) = pure $ PrekeyId (fromIntegral i)
   fromCql _ = Left "PrekeyId: Int expected"
 
 instance Cql ServiceTag where
   ctype = Tagged BigIntColumn
 
   fromCql (CqlBigInt i) = case intToTag i of
-    Just t -> return t
+    Just t -> pure t
     Nothing -> Left $ "unexpected service tag: " ++ show i
   fromCql _ = Left "service tag: int expected"
 
@@ -73,7 +73,7 @@ instance Cql ServiceKey where
     s <- required "size"
     p <- required "pem"
     case (t :: Int32) of
-      0 -> return $! ServiceKey RsaServiceKey s p
+      0 -> pure $! ServiceKey RsaServiceKey s p
       _ -> Left $ "Unexpected service key type: " ++ show t
     where
       required :: Cql r => Text -> Either String r
diff --git a/libs/brig-types/src/Brig/Types/Intra.hs b/libs/brig-types/src/Brig/Types/Intra.hs
index 65e7e822f91..a16610f0b0b 100644
--- a/libs/brig-types/src/Brig/Types/Intra.hs
+++ b/libs/brig-types/src/Brig/Types/Intra.hs
@@ -107,7 +107,7 @@ instance FromJSON UserAccount where
   parseJSON j@(Object o) = do
     u <- parseJSON j
     s <- o .: "status"
-    return $ UserAccount u s
+    pure $ UserAccount u s
   parseJSON _ = mzero
 
 instance ToJSON UserAccount where
diff --git a/libs/brig-types/src/Brig/Types/Team/LegalHold.hs b/libs/brig-types/src/Brig/Types/Team/LegalHold.hs
index 321f65f22ee..5156e6ca63b 100644
--- a/libs/brig-types/src/Brig/Types/Team/LegalHold.hs
+++ b/libs/brig-types/src/Brig/Types/Team/LegalHold.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE OverloadedStrings #-}
 
 -- This file is part of the Wire Server implementation.
@@ -80,7 +79,7 @@ instance FromJSON LegalHoldService where
       <*> o .: "public_key"
 
 legalHoldService :: TeamId -> Fingerprint Rsa -> NewLegalHoldService -> ServiceKey -> LegalHoldService
-legalHoldService tid fpr (NewLegalHoldService u _ t) k = LegalHoldService tid u fpr t k
+legalHoldService tid fpr (NewLegalHoldService u _ t) = LegalHoldService tid u fpr t
 
 viewLegalHoldService :: LegalHoldService -> ViewLegalHoldService
 viewLegalHoldService (LegalHoldService tid u fpr t k) =
diff --git a/libs/brig-types/test/unit/Test/Brig/Types/User.hs b/libs/brig-types/test/unit/Test/Brig/Types/User.hs
index 5605784c55a..a3c2002bc9c 100644
--- a/libs/brig-types/test/unit/Test/Brig/Types/User.hs
+++ b/libs/brig-types/test/unit/Test/Brig/Types/User.hs
@@ -1,11 +1,9 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE QuasiQuotes #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE TypeFamilies #-}
-{-# LANGUAGE ViewPatterns #-}
 {-# OPTIONS_GHC -Wno-orphans #-}
 
 -- This file is part of the Wire Server implementation.
diff --git a/libs/cassandra-util/src/Cassandra/Exec.hs b/libs/cassandra-util/src/Cassandra/Exec.hs
index 6cb9c56129d..ae7589deb37 100644
--- a/libs/cassandra-util/src/Cassandra/Exec.hs
+++ b/libs/cassandra-util/src/Cassandra/Exec.hs
@@ -84,9 +84,9 @@ syncCassandra :: (Functor m, MonadIO m, MonadCatch m) => m a -> m (Either Cassan
 syncCassandra m =
   catches
     (Right <$> m)
-    [ Handler $ \(e :: Error) -> return . Left . Cassandra $ e,
-      Handler $ \(e :: IOException) -> return . Left . Comm $ e,
-      Handler $ \(e :: SomeException) -> return . Left . Other $ e
+    [ Handler $ \(e :: Error) -> pure . Left . Cassandra $ e,
+      Handler $ \(e :: IOException) -> pure . Left . Comm $ e,
+      Handler $ \(e :: SomeException) -> pure . Left . Other $ e
     ]
 
 -- | Stream results of a query.
@@ -122,7 +122,7 @@ paginateWithState q p = do
   r <- runQ q p'
   getResult r >>= \case
     Protocol.RowsResult m b ->
-      return $ PageWithState b (pagingState m)
+      pure $ PageWithState b (pagingState m)
     _ -> throwM $ UnexpectedResponse (hrHost r) (hrResponse r)
 
 paramsPagingState :: Consistency -> a -> Int32 -> Maybe Protocol.PagingState -> QueryParams a
diff --git a/libs/cassandra-util/src/Cassandra/Schema.hs b/libs/cassandra-util/src/Cassandra/Schema.hs
index 4877f8df064..5205078b9ef 100644
--- a/libs/cassandra-util/src/Cassandra/Schema.hs
+++ b/libs/cassandra-util/src/Cassandra/Schema.hs
@@ -130,7 +130,7 @@ versionCheck v = do
       "Schema Version too old! Expecting at least: "
         <> show v
         <> ", but got: "
-        <> fromMaybe "" (show <$> v')
+        <> maybe "" show v'
 
 createKeyspace :: Keyspace -> ReplicationStrategy -> Client ()
 createKeyspace (Keyspace k) rs = void $ schema (cql rs) (params All ())
@@ -231,7 +231,7 @@ waitForSchemaConsistency = do
       mbLocalVersion <- systemLocalVersion
       peers <- systemPeerVersions
       case mbLocalVersion of
-        Just localVersion -> return $ (localVersion, peers)
+        Just localVersion -> pure $ (localVersion, peers)
         Nothing -> error "No system_version in system.local (should never happen)"
     inDisagreement :: (UUID, [UUID]) -> Bool
     inDisagreement (localVersion, peers) = not $ all (== localVersion) peers
@@ -252,43 +252,44 @@ retryWhileN :: (MonadIO m) => Int -> (a -> Bool) -> m a -> m a
 retryWhileN n f m =
   retrying
     (constantDelay 1000000 <> limitRetries n)
-    (const (return . f))
+    (const (pure . f))
     (const m)
 
 -- | The migrationPolicy selects only one and always the same host
 migrationPolicy :: IO Policy
 migrationPolicy = do
   h <- newIORef Nothing
-  return $
+  pure $
     Policy
       { setup = setHost h,
-        onEvent = const $ return (),
+        onEvent = const $ pure (),
         select = readIORef h,
-        acceptable = const $ return True,
+        acceptable = const $ pure True,
         hostCount = fromIntegral . length . maybeToList <$> readIORef h,
         display = ("migrationPolicy: " ++) . show <$> readIORef h,
         current = maybeToList <$> readIORef h
       }
   where
     setHost h (a : _) _ = writeIORef h (Just a)
-    setHost _ _ _ = return ()
+    setHost _ _ _ = pure ()
 
 migrationOptsParser :: Parser MigrationOpts
 migrationOptsParser =
   MigrationOpts
-    <$> ( strOption $
-            long "host"
-              <> metavar "HOST"
-              <> value "localhost"
-              <> help "Cassandra host"
-        )
-    <*> ( option auto $
-            long "port"
-              <> metavar "PORT"
-              <> value 9042
-              <> help "Cassandra port"
-        )
-    <*> ( (fmap pack) . strOption $
+    <$> strOption
+      ( long "host"
+          <> metavar "HOST"
+          <> value "localhost"
+          <> help "Cassandra host"
+      )
+    <*> option
+      auto
+      ( long "port"
+          <> metavar "PORT"
+          <> value 9042
+          <> help "Cassandra port"
+      )
+    <*> ( fmap pack . strOption $
             long "keyspace"
               <> metavar "STRING"
               <> help "Cassandra Keyspace"
@@ -304,7 +305,7 @@ migrationOptsParser =
                       <> help "Replication Map (i.e. \"eu-west:3,us-east:3\")"
                 )
         )
-    <*> ( switch $
-            long "reset"
-              <> help "Reset the keyspace before running migrations"
-        )
+    <*> switch
+      ( long "reset"
+          <> help "Reset the keyspace before running migrations"
+      )
diff --git a/libs/cassandra-util/src/Cassandra/Settings.hs b/libs/cassandra-util/src/Cassandra/Settings.hs
index c20a6dfc3ef..1fb3bf2007c 100644
--- a/libs/cassandra-util/src/Cassandra/Settings.hs
+++ b/libs/cassandra-util/src/Cassandra/Settings.hs
@@ -59,7 +59,7 @@ initialContactsDisco (pack -> srv) url = liftIO $ do
             . _String
           & map unpack
   case ip of
-    i : ii -> return (i :| ii)
+    i : ii -> pure (i :| ii)
     _ -> error "initial-contacts: no IP addresses found."
 
 -- | Puts the address into a list using the same signature as the other initialContacts
diff --git a/libs/dns-util/src/Wire/Network/DNS/SRV.hs b/libs/dns-util/src/Wire/Network/DNS/SRV.hs
index ee05c3b8373..597eaa9afcb 100644
--- a/libs/dns-util/src/Wire/Network/DNS/SRV.hs
+++ b/libs/dns-util/src/Wire/Network/DNS/SRV.hs
@@ -117,7 +117,7 @@ orderSrvResult =
     >>> fmap concat
   where
     orderSublist :: [SrvEntry] -> IO [SrvEntry]
-    orderSublist [] = return []
+    orderSublist [] = pure []
     orderSublist sublist = do
       -- Compute the running sum, as well as the total sum of the sublist.
       -- Add the running sum to the SRV tuples.
@@ -129,10 +129,10 @@ orderSrvResult =
       -- than or equal to the random number.
       let (beginning, (firstSrv, _), end) =
             case break (\(_, running) -> randomNumber <= running) sublistWithRunning of
-              (b, (c : e)) -> (b, c, e)
+              (b, c : e) -> (b, c, e)
               _ -> error "orderSrvResult: no record with running sum greater than random number"
       -- Remove the running total number from the remaining elements.
-      let remainingSrvs = map fst (concat [beginning, end])
+      let remainingSrvs = map fst (beginning ++ end)
       -- Repeat the ordering procedure on the remaining elements.
       rest <- orderSublist remainingSrvs
-      return $ firstSrv : rest
+      pure $ firstSrv : rest
diff --git a/libs/extended/src/Servant/API/Extended.hs b/libs/extended/src/Servant/API/Extended.hs
index 7f71777dd77..e0457115995 100644
--- a/libs/extended/src/Servant/API/Extended.hs
+++ b/libs/extended/src/Servant/API/Extended.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-
 -- This file is part of the Wire Server implementation.
 --
 -- Copyright (C) 2022 Wire Swiss GmbH <opensource@wire.com>
diff --git a/libs/extended/src/System/Logger/Extended.hs b/libs/extended/src/System/Logger/Extended.hs
index 9bf0cdddcf5..34de83ee421 100644
--- a/libs/extended/src/System/Logger/Extended.hs
+++ b/libs/extended/src/System/Logger/Extended.hs
@@ -149,9 +149,10 @@ netStringsToLogFormat False = Plain
 mkLogger :: Log.Level -> Maybe (Last Bool) -> Maybe (Last LogFormat) -> IO Log.Logger
 mkLogger lvl useNetstrings logFormat = do
   mkLoggerNew lvl $
-    case (fmap netStringsToLogFormat <$> useNetstrings) <> logFormat of
-      Just x -> getLast x
-      Nothing -> Plain
+    maybe
+      Plain
+      getLast
+      ((fmap netStringsToLogFormat <$> useNetstrings) <> logFormat)
 
 -- | Version of mkLogger that doesn't support the deprecated useNetstrings option
 mkLoggerNew :: Log.Level -> LogFormat -> IO Log.Logger
diff --git a/libs/galley-types/src/Galley/Types/Conversations/Roles.hs b/libs/galley-types/src/Galley/Types/Conversations/Roles.hs
index c33dc0add21..48788a81168 100644
--- a/libs/galley-types/src/Galley/Types/Conversations/Roles.hs
+++ b/libs/galley-types/src/Galley/Types/Conversations/Roles.hs
@@ -53,7 +53,7 @@ isActionAllowed action rn
 
 -- | Custom RoleNames _must not_ start with `wire_`
 isCustomRoleName :: RoleName -> Bool
-isCustomRoleName (fromRoleName -> r) = isValidRoleName r && (not $ "wire_" `T.isPrefixOf` r)
+isCustomRoleName (fromRoleName -> r) = isValidRoleName r && not ("wire_" `T.isPrefixOf` r)
 
 roleNameToActions :: RoleName -> Maybe (Set Action)
 roleNameToActions r = roleActions <$> toConvRole r Nothing
diff --git a/libs/galley-types/test/unit/Test/Galley/Types.hs b/libs/galley-types/test/unit/Test/Galley/Types.hs
index 7f59c06e49f..996022d8b2a 100644
--- a/libs/galley-types/test/unit/Test/Galley/Types.hs
+++ b/libs/galley-types/test/unit/Test/Galley/Types.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# OPTIONS_GHC -Wno-orphans -Wno-incomplete-uni-patterns #-}
 
diff --git a/libs/gundeck-types/src/Gundeck/Types/Common.hs b/libs/gundeck-types/src/Gundeck/Types/Common.hs
index fad0df493de..37208a13398 100644
--- a/libs/gundeck-types/src/Gundeck/Types/Common.hs
+++ b/libs/gundeck-types/src/Gundeck/Types/Common.hs
@@ -58,4 +58,4 @@ instance FromByteString URI where
   parser = takeByteString >>= parse . Bytes.unpack
 
 parse :: (Monad m, MonadFail m) => String -> m URI
-parse = maybe (fail "Invalid URI") (return . URI) . Net.parseURI
+parse = maybe (fail "Invalid URI") (pure . URI) . Net.parseURI
diff --git a/libs/gundeck-types/src/Gundeck/Types/Presence.hs b/libs/gundeck-types/src/Gundeck/Types/Presence.hs
index 01895b6ccd3..40d9aa37da8 100644
--- a/libs/gundeck-types/src/Gundeck/Types/Presence.hs
+++ b/libs/gundeck-types/src/Gundeck/Types/Presence.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE OverloadedStrings #-}
 
 -- This file is part of the Wire Server implementation.
diff --git a/libs/gundeck-types/src/Gundeck/Types/Push/V2.hs b/libs/gundeck-types/src/Gundeck/Types/Push/V2.hs
index f1b708faddb..c491d89963f 100644
--- a/libs/gundeck-types/src/Gundeck/Types/Push/V2.hs
+++ b/libs/gundeck-types/src/Gundeck/Types/Push/V2.hs
@@ -101,9 +101,9 @@ data Route
   deriving (Eq, Ord, Enum, Bounded, Show)
 
 instance FromJSON Route where
-  parseJSON (String "any") = return RouteAny
-  parseJSON (String "direct") = return RouteDirect
-  parseJSON (String "native") = return RouteNative
+  parseJSON (String "any") = pure RouteAny
+  parseJSON (String "direct") = pure RouteDirect
+  parseJSON (String "native") = pure RouteNative
   parseJSON x = fail $ "Invalid routing: " ++ show (encode x)
 
 instance ToJSON Route where
diff --git a/libs/metrics-core/src/Data/Metrics.hs b/libs/metrics-core/src/Data/Metrics.hs
index 85ef0048451..b5fdcbd14c2 100644
--- a/libs/metrics-core/src/Data/Metrics.hs
+++ b/libs/metrics-core/src/Data/Metrics.hs
@@ -150,7 +150,7 @@ toInfo (Path p) =
 getOrCreate :: (MonadIO m, Eq k, Hashable k) => IORef (HashMap k v) -> k -> IO v -> m v
 getOrCreate mapRef key initializer = liftIO $ do
   hMap <- readIORef mapRef
-  maybe initialize return (HM.lookup key hMap)
+  maybe initialize pure (HM.lookup key hMap)
   where
     initialize = do
       val <- initializer
diff --git a/libs/metrics-wai/src/Data/Metrics/Test.hs b/libs/metrics-wai/src/Data/Metrics/Test.hs
index e7e34363ee5..50e07b98119 100644
--- a/libs/metrics-wai/src/Data/Metrics/Test.hs
+++ b/libs/metrics-wai/src/Data/Metrics/Test.hs
@@ -44,7 +44,7 @@ pathsConsistencyCheck :: Paths -> [SiteConsistencyError]
 pathsConsistencyCheck (Paths forest) = mconcat $ go [] <$> forest
   where
     go :: [PathSegment] -> Tree.Tree PathSegment -> [SiteConsistencyError]
-    go prefix (Tree.Node root trees) = maybeToList here <> (mconcat $ go (root : prefix) <$> trees)
+    go prefix (Tree.Node root trees) = maybeToList here <> mconcat (go (root : prefix) <$> trees)
       where
         here = findSiteConsistencyError (reverse $ root : prefix) trees
     findSiteConsistencyError :: [PathSegment] -> Tree.Forest PathSegment -> Maybe SiteConsistencyError
diff --git a/libs/metrics-wai/src/Data/Metrics/WaiRoute.hs b/libs/metrics-wai/src/Data/Metrics/WaiRoute.hs
index 92b953d377b..cd8a993c2cb 100644
--- a/libs/metrics-wai/src/Data/Metrics/WaiRoute.hs
+++ b/libs/metrics-wai/src/Data/Metrics/WaiRoute.hs
@@ -1,6 +1,4 @@
-{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE ViewPatterns #-}
 
 -- This file is part of the Wire Server implementation.
 --
diff --git a/libs/ropes/src/Ropes/Nexmo.hs b/libs/ropes/src/Ropes/Nexmo.hs
index 1de3ec41ad7..ba770c4db4d 100644
--- a/libs/ropes/src/Ropes/Nexmo.hs
+++ b/libs/ropes/src/Ropes/Nexmo.hs
@@ -2,7 +2,6 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE ViewPatterns #-}
 
 -- This file is part of the Wire Server implementation.
 --
@@ -113,18 +112,18 @@ data MessageErrorStatus
   deriving (Eq, Show)
 
 instance FromJSON MessageErrorStatus where
-  parseJSON "1" = return MessageThrottled
-  parseJSON "5" = return MessageInternal
-  parseJSON "6" = return MessageUnroutable
-  parseJSON "7" = return MessageNumBarred
-  parseJSON "8" = return MessagePartnerAccountBarred
-  parseJSON "9" = return MessagePartnerQuotaExceeded
-  parseJSON "12" = return MessageTooLong
-  parseJSON "13" = return MessageCommunicationFailed
-  parseJSON "15" = return MessageInvalidSenderAddress
-  parseJSON "19" = return MessageFacilityNotAllowed
-  parseJSON "20" = return MessageInvalidMessageClass
-  parseJSON _ = return MessageOther
+  parseJSON "1" = pure MessageThrottled
+  parseJSON "5" = pure MessageInternal
+  parseJSON "6" = pure MessageUnroutable
+  parseJSON "7" = pure MessageNumBarred
+  parseJSON "8" = pure MessagePartnerAccountBarred
+  parseJSON "9" = pure MessagePartnerQuotaExceeded
+  parseJSON "12" = pure MessageTooLong
+  parseJSON "13" = pure MessageCommunicationFailed
+  parseJSON "15" = pure MessageInvalidSenderAddress
+  parseJSON "19" = pure MessageFacilityNotAllowed
+  parseJSON "20" = pure MessageInvalidMessageClass
+  parseJSON _ = pure MessageOther
 
 data MessageErrorResponse = MessageErrorResponse
   { erStatus :: !MessageErrorStatus,
@@ -145,16 +144,16 @@ newtype ParseError = ParseError String
 instance Exception ParseError
 
 instance FromJSON MessageId where
-  parseJSON = withText "MessageId" $ return . MessageId
+  parseJSON = withText "MessageId" $ pure . MessageId
 
 instance ToJSON MessageId where
   toJSON = String . messageIdText
 
 instance FromJSON Charset where
-  parseJSON "text" = return GSM7
-  parseJSON "binary" = return GSM8
-  parseJSON "unicode" = return UCS2
-  parseJSON x = fail $ "Unsupported charset " <> (show x)
+  parseJSON "text" = pure GSM7
+  parseJSON "binary" = pure GSM8
+  parseJSON "unicode" = pure UCS2
+  parseJSON x = fail $ "Unsupported charset " <> show x
 
 instance ToJSON Charset where
   toJSON GSM7 = "text"
@@ -179,8 +178,8 @@ parseMessageResponse = withObject "nexmo-response" $ \o -> do
   xs <- o .: "messages"
   ys <- sequence <$> mapM parseMessageFeedback xs
   case ys of
-    Left e -> return $ Left e
-    Right (f : fs) -> return $ Right $ MessageResponse (f :| fs)
+    Left e -> pure $ Left e
+    Right (f : fs) -> pure $ Right $ MessageResponse (f :| fs)
     Right _ -> fail "Must have at least one message-id"
 
 -- * Call related
@@ -207,14 +206,14 @@ data CallErrorStatus
   deriving (Eq, Show)
 
 instance FromJSON CallErrorStatus where
-  parseJSON "1" = return CallThrottled
-  parseJSON "5" = return CallInternal
-  parseJSON "6" = return CallDestinationNotPermitted
-  parseJSON "7" = return CallDestinationBarred
-  parseJSON "9" = return CallPartnerQuotaExceeded
-  parseJSON "15" = return CallInvalidDestinationAddress
-  parseJSON "17" = return CallUnroutable
-  parseJSON _ = return CallOther
+  parseJSON "1" = pure CallThrottled
+  parseJSON "5" = pure CallInternal
+  parseJSON "6" = pure CallDestinationNotPermitted
+  parseJSON "7" = pure CallDestinationBarred
+  parseJSON "9" = pure CallPartnerQuotaExceeded
+  parseJSON "15" = pure CallInvalidDestinationAddress
+  parseJSON "17" = pure CallUnroutable
+  parseJSON _ = pure CallOther
 
 data CallErrorResponse = CallErrorResponse
   { caStatus :: !CallErrorStatus,
@@ -264,7 +263,7 @@ sendCall cr mgr call = httpLbs req mgr >>= parseResult
   where
     parseResult res = case parseEither parseCallResponse =<< eitherDecode (responseBody res) of
       Left e -> throwIO $ ParseError e
-      Right r -> either throwIO return r
+      Right r -> either throwIO pure r
     req =
       defaultRequest
         { method = "POST",
@@ -331,7 +330,7 @@ sendMessages cr mgr msgs = forM msgs $ \m -> httpLbs (req m) mgr >>= parseResult
   where
     parseResult res = case parseEither parseMessageResponse =<< eitherDecode (responseBody res) of
       Left e -> throwIO $ ParseError e
-      Right r -> either throwIO return r
+      Right r -> either throwIO pure r
     req m =
       defaultRequest
         { method = "POST",
diff --git a/libs/ropes/src/Ropes/Twilio.hs b/libs/ropes/src/Ropes/Twilio.hs
index eefbf53226a..5696708135e 100644
--- a/libs/ropes/src/Ropes/Twilio.hs
+++ b/libs/ropes/src/Ropes/Twilio.hs
@@ -142,9 +142,9 @@ instance FromJSON CarrierInfo where
 instance FromJSON PhoneType where
   parseJSON = withText "PhoneType" $ \t ->
     case t of
-      "mobile" -> return Mobile
-      "landline" -> return Landline
-      "voip" -> return VoIp
+      "mobile" -> pure Mobile
+      "landline" -> pure Landline
+      "voip" -> pure VoIp
       x -> fail $ "Unexpected phone type: " ++ show x
 
 -- * Functions
@@ -161,7 +161,7 @@ sendMessages cr mgr msgs = forM msgs $ \m -> do
   rsp <- httpLbs req mgr
   if responseStatus rsp == status201
     then case eitherDecode (responseBody rsp) of
-      Right r -> return $ msgId r
+      Right r -> pure $ msgId r
       Left e -> throwIO $ ParseError e
     else case eitherDecode (responseBody rsp) of
       Right e -> throwIO (e :: ErrorResponse)
@@ -194,7 +194,7 @@ lookupPhone cr mgr phone detail country = do
   rsp <- httpLbs req mgr
   if responseStatus rsp == status200
     then case eitherDecode (responseBody rsp) of
-      Right r -> return r
+      Right r -> pure r
       Left e -> throwIO $ ParseError e
     else case eitherDecode (responseBody rsp) of
       Right e -> throwIO (e :: ErrorResponse)
diff --git a/libs/schema-profunctor/test/unit/Test/Data/Schema.hs b/libs/schema-profunctor/test/unit/Test/Data/Schema.hs
index fac73016ea3..0a4c79d1929 100644
--- a/libs/schema-profunctor/test/unit/Test/Data/Schema.hs
+++ b/libs/schema-profunctor/test/unit/Test/Data/Schema.hs
@@ -351,7 +351,7 @@ testNullable =
             A.parse (schemaIn sch) A.Null @?= Success Nothing,
           testCase "Nullable schemas should produce either a value or null" $ do
             schemaOut sch (Just 5) @?= Just (A.Number 5)
-            schemaOut sch Nothing @?= Just (A.Null),
+            schemaOut sch Nothing @?= Just A.Null,
           testCase "Nullable schemas should return an error when parsing invalid non-null values" $ do
             case A.parse (schemaIn sch) (A.String "foo") of
               Success _ -> assertFailure "fromJSON should fail"
diff --git a/libs/ssl-util/src/Ssl/Util.hs b/libs/ssl-util/src/Ssl/Util.hs
index 5fc17fc3da6..9f9d8ece4e4 100644
--- a/libs/ssl-util/src/Ssl/Util.hs
+++ b/libs/ssl-util/src/Ssl/Util.hs
@@ -128,7 +128,7 @@ verifyFingerprint ::
   SSL ->
   IO ()
 verifyFingerprint hash fprs ssl = do
-  cert <- SSL.getPeerCertificate ssl >>= maybe (throwIO PinMissingCert) return
+  cert <- SSL.getPeerCertificate ssl >>= maybe (throwIO PinMissingCert) pure
   pkey <- X509.getPublicKey cert
   mfpr <- hash pkey
   case mfpr of
@@ -161,13 +161,13 @@ rsaFingerprint d k = fmap (digestLBS d . toLazyByteString) $ do
   let s = rsaSize k
   n <- integerToMPI (rsaN k)
   e <- integerToMPI (rsaE k)
-  return $! intDec s <> byteString n <> byteString e
+  pure $! intDec s <> byteString n <> byteString e
 
 -- | 'verifyFingerprint' specialised to 'RSAPubKey's using 'rsaFingerprint'.
 verifyRsaFingerprint :: Digest -> [ByteString] -> SSL -> IO ()
 verifyRsaFingerprint d = verifyFingerprint $ \pk ->
   case toPublicKey pk of
-    Nothing -> return Nothing
+    Nothing -> pure Nothing
     Just k -> Just <$> rsaFingerprint d (k :: RSAPubKey)
 
 -- [Note: Hostname verification]
diff --git a/libs/tasty-cannon/src/Test/Tasty/Cannon.hs b/libs/tasty-cannon/src/Test/Tasty/Cannon.hs
index 57c8cfd78e9..f7f556886f1 100644
--- a/libs/tasty-cannon/src/Test/Tasty/Cannon.hs
+++ b/libs/tasty-cannon/src/Test/Tasty/Cannon.hs
@@ -114,7 +114,7 @@ connectAsMaybeClient can uid client conn = liftIO $ do
   nchan <- newTChanIO
   latch <- newEmptyMVar
   wsapp <- run can uid client conn (clientApp nchan latch)
-  return $ WebSocket nchan latch wsapp
+  pure $ WebSocket nchan latch wsapp
 
 close :: MonadIO m => WebSocket -> m ()
 close ws = liftIO $ do
@@ -299,7 +299,7 @@ awaitMatch t ws match = go [] []
           do
             liftIO (match n)
             refill buf
-            return (Right n)
+            pure (Right n)
             `catchAll` \e -> case asyncExceptionFromException e of
               Just x -> throwM (x :: SomeAsyncException)
               Nothing ->
@@ -307,7 +307,7 @@ awaitMatch t ws match = go [] []
                  in go (n : buf) (e' : errs)
         Nothing -> do
           refill buf
-          return (Left (MatchTimeout errs))
+          pure (Left (MatchTimeout errs))
     refill = mapM_ (liftIO . atomically . writeTChan (wsChan ws))
 
 awaitMatch_ ::
@@ -367,7 +367,7 @@ assertMatchN_ ::
 assertMatchN_ t wss f = void $ assertMatchN t wss f
 
 assertSuccess :: (HasCallStack, MonadIO m, MonadThrow m) => Either MatchTimeout Notification -> m Notification
-assertSuccess = either throwM return
+assertSuccess = either throwM pure
 
 assertNoEvent :: (HasCallStack, MonadIO m, MonadCatch m) => Timeout -> [WebSocket] -> m ()
 assertNoEvent t ww = do
@@ -393,7 +393,7 @@ unpackPayload = fmap decodeEvent . ntfPayload
 randomConnId :: MonadIO m => m ConnId
 randomConnId = liftIO $ do
   r <- randomIO :: IO Word32
-  return . ConnId $ C.pack $ show r
+  pure . ConnId $ C.pack $ show r
 
 -----------------------------------------------------------------------------
 -- Internals
@@ -419,7 +419,7 @@ run cannon@(($ Http.defaultRequest) -> ca) uid client connId app = liftIO $ do
   stat <- poll wsapp
   case stat of
     Just (Left ex) -> throwIO ex
-    _ -> waitForRegistry numRetries >> return wsapp
+    _ -> waitForRegistry numRetries >> pure wsapp
   where
     caHost = C.unpack (Http.host ca)
     caPort = Http.port ca
diff --git a/libs/types-common-aws/src/Util/Test/SQS.hs b/libs/types-common-aws/src/Util/Test/SQS.hs
index a0c86086bd5..e68e684484e 100644
--- a/libs/types-common-aws/src/Util/Test/SQS.hs
+++ b/libs/types-common-aws/src/Util/Test/SQS.hs
@@ -2,7 +2,6 @@
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE UndecidableInstances #-}
 
@@ -62,7 +61,7 @@ readAndDeleteAllUntilEmpty url = do
   firstBatch <- fromMaybe [] . view SQS.receiveMessageResponse_messages <$> sendEnv (receive 1 url)
   readUntilEmpty firstBatch firstBatch
   where
-    readUntilEmpty acc [] = return acc
+    readUntilEmpty acc [] = pure acc
     readUntilEmpty acc msgs = do
       forM_ msgs $ deleteMessage url
       newMsgs <- fromMaybe [] . view SQS.receiveMessageResponse_messages <$> sendEnv (receive 1 url)
@@ -101,13 +100,14 @@ fetchMessage url label callback = do
 
 parseDeleteMessage :: (Monad m, Message a, MonadIO m, MonadReader AWS.Env m, MonadResource m) => Text -> SQS.Message -> m (Maybe a)
 parseDeleteMessage url m = do
-  evt <- case (>>= decodeMessage) . B64.decode . Text.encodeUtf8 <$> (m ^. SQS.message_body) of
-    Just (Right e) -> return (Just e)
+  let decodedMessage = decodeMessage <=< (B64.decode . Text.encodeUtf8)
+  evt <- case decodedMessage <$> (m ^. SQS.message_body) of
+    Just (Right e) -> pure (Just e)
     _ -> do
       liftIO $ print ("Failed to parse SQS message or event" :: String)
-      return Nothing
+      pure Nothing
   deleteMessage url m
-  return evt
+  pure evt
 
 queueMessage :: (MonadReader AWS.Env m, Message a, MonadResource m) => Text -> a -> m ()
 queueMessage url e = do
@@ -143,10 +143,10 @@ tryMatch label tries url callback = go tries
     check e =
       do
         liftIO $ callback label e
-        return (Right $ show e)
+        pure (Right $ show e)
         `catchAll` \ex -> case asyncExceptionFromException ex of
           Just x -> throwM (x :: SomeAsyncException)
-          Nothing -> return . Left $ MatchFailure (e, ex)
+          Nothing -> pure . Left $ MatchFailure (e, ex)
 
 sendEnv :: (MonadReader AWS.Env m, MonadResource m, AWS.AWSRequest a) => a -> m (AWS.AWSResponse a)
 sendEnv x = flip AWS.send x =<< ask
diff --git a/libs/types-common/src/Data/Id.hs b/libs/types-common/src/Data/Id.hs
index b587f102d15..bcdd57aa121 100644
--- a/libs/types-common/src/Data/Id.hs
+++ b/libs/types-common/src/Data/Id.hs
@@ -61,6 +61,7 @@ import qualified Data.Aeson.Key as Key
 import qualified Data.Aeson.Types as A
 import Data.Attoparsec.ByteString ((<?>))
 import qualified Data.Attoparsec.ByteString.Char8 as Atto
+import Data.Bifunctor (first)
 import Data.Binary
 import Data.ByteString.Builder (byteString)
 import Data.ByteString.Conversion
@@ -173,7 +174,7 @@ instance Show (Id a) where
   show = UUID.toString . toUUID
 
 instance Read (Id a) where
-  readsPrec n = map (\(a, x) -> (Id a, x)) . readsPrec n
+  readsPrec n = map (first Id) . readsPrec n
 
 instance FromByteString (Id a) where
   parser = do
@@ -189,7 +190,7 @@ instance FromByteString (Id a) where
         void $ Atto.count 12 hexDigit
     case UUID.fromASCIIBytes match of
       Nothing -> fail "Invalid UUID"
-      Just ui -> return (Id ui)
+      Just ui -> pure (Id ui)
     where
       matching = fmap fst . Atto.match
       hexDigit = Atto.satisfy Char.isHexDigit <?> "hexadecimal digit"
@@ -315,7 +316,7 @@ instance EncodeWire ClientId where
   encodeWire t = encodeWire t . client
 
 instance DecodeWire ClientId where
-  decodeWire (DelimitedField _ x) = either fail return (runParser parser x)
+  decodeWire (DelimitedField _ x) = either fail pure (runParser parser x)
   decodeWire _ = fail "Invalid ClientId"
 
 -- BotId -----------------------------------------------------------------------
@@ -339,7 +340,7 @@ instance Show BotId where
   show = show . botUserId
 
 instance Read BotId where
-  readsPrec n = map (\(a, x) -> (BotId a, x)) . readsPrec n
+  readsPrec n = map (first BotId) . readsPrec n
 
 deriving instance Cql BotId
 
diff --git a/libs/types-common/src/Data/Misc.hs b/libs/types-common/src/Data/Misc.hs
index 85ad78537c0..0807be0e76e 100644
--- a/libs/types-common/src/Data/Misc.hs
+++ b/libs/types-common/src/Data/Misc.hs
@@ -103,7 +103,7 @@ instance FromByteString IpAddr where
     s <- Chars.takeWhile1 (not . isSpace)
     case readMaybe (unpack s) of
       Nothing -> fail "Failed parsing bytestring as IpAddr."
-      Just ip -> return (IpAddr ip)
+      Just ip -> pure (IpAddr ip)
 
 instance ToByteString IpAddr where
   builder = string8 . show . ipAddr
@@ -136,7 +136,7 @@ instance FromJSON IpAddr where
   parseJSON = A.withText "IpAddr" $ \txt ->
     case readMaybe (Text.unpack txt) of
       Nothing -> fail "Failed parsing IP address."
-      Just ip -> return (IpAddr ip)
+      Just ip -> pure (IpAddr ip)
 
 instance ToJSON Port where
   toJSON (Port p) = toJSON p
@@ -198,7 +198,7 @@ instance Cql Latitude where
 
   toCql (Latitude x) = CqlDouble x
 
-  fromCql (CqlDouble x) = return (Latitude x)
+  fromCql (CqlDouble x) = pure (Latitude x)
   fromCql _ = Left "Latitude: Expected CqlDouble."
 
 instance Cql Longitude where
@@ -206,7 +206,7 @@ instance Cql Longitude where
 
   toCql (Longitude x) = CqlDouble x
 
-  fromCql (CqlDouble x) = return (Longitude x)
+  fromCql (CqlDouble x) = pure (Longitude x)
   fromCql _ = Left "Longitude: Expected CqlDouble."
 
 --------------------------------------------------------------------------------
@@ -329,7 +329,7 @@ instance Cql (Fingerprint a) where
   ctype = Tagged BlobColumn
   toCql = CqlBlob . toByteString
 
-  fromCql (CqlBlob b) = return (Fingerprint (toStrict b))
+  fromCql (CqlBlob b) = pure (Fingerprint (toStrict b))
   fromCql _ = Left "Fingerprint: Expected CqlBlob"
 
 instance Arbitrary (Fingerprint Rsa) where
diff --git a/libs/types-common/src/Data/Range.hs b/libs/types-common/src/Data/Range.hs
index 5589004e35c..137b1ed8403 100644
--- a/libs/types-common/src/Data/Range.hs
+++ b/libs/types-common/src/Data/Range.hs
@@ -116,7 +116,7 @@ instance ToJSON a => ToJSON (Range n m a) where
   toJSON = toJSON . fromRange
 
 instance (Within a n m, FromJSON a) => FromJSON (Range n m a) where
-  parseJSON v = parseJSON v >>= maybe (msg sing sing) return . checked
+  parseJSON v = parseJSON v >>= maybe (msg sing sing) pure . checked
     where
       msg :: Bounds a => SNat n -> SNat m -> Aeson.Parser (Range n m a)
       msg sn sm = fail (errorMsg (fromSing sn) (fromSing sm) "")
@@ -184,7 +184,7 @@ instance (Within a n m, ToSchema a, HasRangedSchemaDocModifier NamedSwaggerDoc a
 instance (Within a n m, Cql a) => Cql (Range n m a) where
   ctype = retag (ctype :: Tagged a ColumnType)
   toCql = toCql . fromRange
-  fromCql c = fromCql c >>= maybe (msg sing sing) return . checked
+  fromCql c = fromCql c >>= maybe (msg sing sing) pure . checked
     where
       msg :: Bounds a => SNat n -> SNat m -> Either String (Range n m a)
       msg sn sm = Left (errorMsg (fromSing sn) (fromSing sm) "")
@@ -423,7 +423,7 @@ instance (Within a n m, Read a) => Read (Range n m a) where
 -----------------------------------------------------------------------------
 
 instance (Within a n m, FromByteString a) => FromByteString (Range n m a) where
-  parser = parser >>= maybe (msg sing sing) return . checked
+  parser = parser >>= maybe (msg sing sing) pure . checked
     where
       msg :: Bounds a => SNat n -> SNat m -> Atto.Parser (Range n m a)
       msg sn sm = fail (errorMsg (fromSing sn) (fromSing sm) "")
@@ -496,8 +496,7 @@ genRangeAsciiText ::
   (HasCallStack, KnownNat n, KnownNat m, LTE n m, AsciiChars c) =>
   Gen (AsciiChar c) ->
   Gen (Range n m (AsciiText c))
-genRangeAsciiText gc =
-  genRange @n @m fromAsciiChars gc
+genRangeAsciiText = genRange @n @m fromAsciiChars
 
 genRange ::
   forall (n :: Nat) (m :: Nat) (a :: *) (b :: *).
diff --git a/libs/types-common/src/Data/Text/Ascii.hs b/libs/types-common/src/Data/Text/Ascii.hs
index 0a993c3a1a8..bc669d5bd61 100644
--- a/libs/types-common/src/Data/Text/Ascii.hs
+++ b/libs/types-common/src/Data/Text/Ascii.hs
@@ -4,7 +4,6 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE TypeFamilies #-}
-{-# LANGUAGE TypeSynonymInstances #-}
 
 -- This file is part of the Wire Server implementation.
 --
diff --git a/libs/types-common/src/Util/Options.hs b/libs/types-common/src/Util/Options.hs
index 95d269110af..c3991f40180 100644
--- a/libs/types-common/src/Util/Options.hs
+++ b/libs/types-common/src/Util/Options.hs
@@ -47,31 +47,31 @@ instance FromByteString AWSEndpoint where
   parser = do
     url <- uriParser strictURIParserOptions
     secure <- case url ^. uriSchemeL . schemeBSL of
-      "https" -> return True
-      "http" -> return False
+      "https" -> pure True
+      "http" -> pure False
       x -> fail ("Unsupported scheme: " ++ show x)
-    host <- case (url ^. authorityL <&> view (authorityHostL . hostBSL)) of
-      Just h -> return h
+    host <- case url ^. authorityL <&> view (authorityHostL . hostBSL) of
+      Just h -> pure h
       Nothing -> fail ("No host in: " ++ show url)
     port <- case urlPort url of
-      Just p -> return p
+      Just p -> pure p
       Nothing ->
-        return $
+        pure $
           if secure
             then 443
             else 80
-    return $ AWSEndpoint host secure port
+    pure $ AWSEndpoint host secure port
 
 instance FromJSON AWSEndpoint where
   parseJSON =
     withText "AWSEndpoint" $
-      either fail return . runParser parser . encodeUtf8
+      either fail pure . runParser parser . encodeUtf8
 
 urlPort :: URIRef Absolute -> Maybe Int
 urlPort u = do
   a <- u ^. authorityL
   p <- a ^. authorityPortL
-  return (fromIntegral (p ^. portNumberL))
+  pure (fromIntegral (p ^. portNumberL))
 
 makeLenses ''AWSEndpoint
 
@@ -109,8 +109,8 @@ loadSecret (FilePathSecrets p) = do
   path <- canonicalizePath p
   exists <- doesFileExist path
   if exists
-    then return . over _Left show . decodeEither' =<< BS.readFile path
-    else return (Left "File doesn't exist")
+    then over _Left show . decodeEither' <$> BS.readFile path
+    else pure (Left "File doesn't exist")
 
 getOptions ::
   FromJSON a =>
@@ -130,7 +130,7 @@ getOptions desc pars defaultPath = do
       configFile <- decodeFileEither path
       case configFile of
         Left e -> fail $ show e
-        Right o -> return o
+        Right o -> pure o
     -- Config doesn't exist but at least we have a CLI options parser
     (False, Just p) -> do
       hPutStrLn stderr $
@@ -160,7 +160,7 @@ parseConfigPath defaultPath desc = do
           <> value defaultPath
 
 parseAWSEndpoint :: ReadM AWSEndpoint
-parseAWSEndpoint = readerAsk >>= maybe (error "Could not parse AWS endpoint") return . fromByteString . fromString
+parseAWSEndpoint = readerAsk >>= maybe (error "Could not parse AWS endpoint") pure . fromByteString . fromString
 
 discoUrlParser :: Parser Text
 discoUrlParser =
diff --git a/libs/types-common/src/Util/Options/Common.hs b/libs/types-common/src/Util/Options/Common.hs
index 13e52e51977..39adc0092f3 100644
--- a/libs/types-common/src/Util/Options/Common.hs
+++ b/libs/types-common/src/Util/Options/Common.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE DeriveGeneric #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE TemplateHaskell #-}
-
 -- This file is part of the Wire Server implementation.
 --
 -- Copyright (C) 2022 Wire Swiss GmbH <opensource@wire.com>
@@ -50,7 +46,7 @@ toOptionFieldName = defaultOptions {fieldLabelModifier = lowerFirst . dropPrefix
     dropPrefix :: String -> String
     dropPrefix = dropWhile (not . isUpper)
 
-optOrEnv :: (a -> b) -> (Maybe a) -> (String -> b) -> String -> IO b
+optOrEnv :: (a -> b) -> Maybe a -> (String -> b) -> String -> IO b
 optOrEnv getter conf reader var = case conf of
   Nothing -> reader <$> getEnv var
   Just c -> pure $ getter c
diff --git a/libs/types-common/src/Util/Test.hs b/libs/types-common/src/Util/Test.hs
index e83d190dd81..33a185e713c 100644
--- a/libs/types-common/src/Util/Test.hs
+++ b/libs/types-common/src/Util/Test.hs
@@ -1,6 +1,4 @@
-{-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE TemplateHaskell #-}
 
 -- This file is part of the Wire Server implementation.
 --
@@ -32,12 +30,12 @@ newtype IntegrationConfigFile = IntegrationConfigFile String
 instance IsOption IntegrationConfigFile where
   defaultValue = IntegrationConfigFile "/etc/wire/integration/integration.yaml"
   parseValue = fmap IntegrationConfigFile . safeRead
-  optionName = return "integration-config"
-  optionHelp = return "Integration config file to read from"
+  optionName = pure "integration-config"
+  optionHelp = pure "Integration config file to read from"
   optionCLParser =
     fmap IntegrationConfigFile $
       strOption $
-        ( short (untag (return 'i' :: Tagged IntegrationConfigFile Char))
+        ( short (untag (pure 'i' :: Tagged IntegrationConfigFile Char))
             <> long (untag (optionName :: Tagged IntegrationConfigFile String))
             <> help (untag (optionHelp :: Tagged IntegrationConfigFile String))
         )
diff --git a/libs/wai-utilities/src/Network/Wai/Utilities/Error.hs b/libs/wai-utilities/src/Network/Wai/Utilities/Error.hs
index bd8f127c44e..9bd1f39d154 100644
--- a/libs/wai-utilities/src/Network/Wai/Utilities/Error.hs
+++ b/libs/wai-utilities/src/Network/Wai/Utilities/Error.hs
@@ -79,7 +79,7 @@ instance ToJSON Error where
         "label" .= l,
         "message" .= m
       ]
-        ++ fromMaybe [] (fmap dataFields md)
+        ++ maybe [] dataFields md
     where
       dataFields :: ErrorData -> [Pair]
       dataFields d = ["data" .= d]
diff --git a/libs/wai-utilities/src/Network/Wai/Utilities/Request.hs b/libs/wai-utilities/src/Network/Wai/Utilities/Request.hs
index c07d29782ae..878311f1640 100644
--- a/libs/wai-utilities/src/Network/Wai/Utilities/Request.hs
+++ b/libs/wai-utilities/src/Network/Wai/Utilities/Request.hs
@@ -82,7 +82,7 @@ jsonRequest ::
   Predicate r Error (JsonRequest body)
 jsonRequest =
   contentType "application" "json"
-    .&> (return . JsonRequest . getRequest)
+    .&> (pure . JsonRequest . getRequest)
 
 newtype OptionalJsonRequest body = OptionalJsonRequest {fromOptionalJsonRequest :: Request}
 
@@ -92,7 +92,7 @@ optionalJsonRequest ::
   Predicate r Error (OptionalJsonRequest body)
 optionalJsonRequest =
   opt (contentType "application" "json")
-    .&> (return . OptionalJsonRequest . getRequest)
+    .&> (pure . OptionalJsonRequest . getRequest)
 
 ----------------------------------------------------------------------------
 -- Instances
diff --git a/libs/wai-utilities/src/Network/Wai/Utilities/Server.hs b/libs/wai-utilities/src/Network/Wai/Utilities/Server.hs
index ed679c8780d..8bbf5286490 100644
--- a/libs/wai-utilities/src/Network/Wai/Utilities/Server.hs
+++ b/libs/wai-utilities/src/Network/Wai/Utilities/Server.hs
@@ -103,11 +103,11 @@ newSettings (Server h p l m t) = do
   -- (Atomically) initialise the standard metrics, to avoid races.
   void $ gaugeGet (path "net.connections") m
   void $ counterGet (path "net.errors") m
-  return $
+  pure $
     setHost (fromString h)
       . setPort (fromIntegral p)
       . setBeforeMainLoop logStart
-      . setOnOpen (const $ connStart >> return True)
+      . setOnOpen (const $ connStart >> pure True)
       . setOnClose (const connEnd)
       . setTimeout (fromMaybe 300 t)
       $ defaultSettings
@@ -148,7 +148,7 @@ runSettingsWithShutdown s app secs = do
 compile :: Monad m => Routes a m b -> Tree (App m)
 compile routes = Route.prepare (Route.renderer predicateError >> routes)
   where
-    predicateError e = return (encode $ Wai.mkError (P.status e) "client-error" (format e), [jsonContent])
+    predicateError e = pure (encode $ Wai.mkError (P.status e) "client-error" (format e), [jsonContent])
     -- [label] 'source' reason: message
     format e =
       let l = labelStr $ labels e
@@ -277,14 +277,14 @@ emitLByteString :: LByteString -> IO (IO ByteString)
 emitLByteString lbs = do
   tvar <- newTVarIO (cs lbs)
   -- Emit the bytestring on the first read, then always return "" on subsequent reads
-  return . atomically $ swapTVar tvar mempty
+  pure . atomically $ swapTVar tvar mempty
 
 -- | Run the 'Application'; check the response status; if >=500, throw a 'Wai.Error' with
 -- label @"server-error"@ and the body as the error message.
 rethrow5xx :: Logger -> Middleware
 rethrow5xx logger app req k = app req k'
   where
-    k' resp@(WaiInt.ResponseRaw {}) = do
+    k' resp@WaiInt.ResponseRaw {} = do
       -- See Note [Raw Response]
       let logMsg =
             field "canoncalpath" (show $ pathInfo req)
@@ -362,7 +362,7 @@ logErrorMsg :: Wai.Error -> Msg -> Msg
 logErrorMsg (Wai.Error c l m md) =
   field "code" (statusCode c)
     . field "label" l
-    . fromMaybe id (fmap logErrorData md)
+    . maybe id logErrorData md
     . msg (val "\"" +++ m +++ val "\"")
   where
     logErrorData (Wai.FederationErrorData d p) =
diff --git a/libs/wai-utilities/src/Network/Wai/Utilities/ZAuth.hs b/libs/wai-utilities/src/Network/Wai/Utilities/ZAuth.hs
index 14f2fc7a92e..c70d65f7a67 100644
--- a/libs/wai-utilities/src/Network/Wai/Utilities/ZAuth.hs
+++ b/libs/wai-utilities/src/Network/Wai/Utilities/ZAuth.hs
@@ -73,7 +73,7 @@ zauthType = zheader "Z-Type"
 zauth :: HasHeaders r => ZAuthType -> Predicate r Error ()
 zauth t = do
   r <- zauthType
-  return $ case r of
+  pure $ case r of
     Okay _ z | z == t -> Okay 0 ()
     _ -> Fail accessDenied
 
diff --git a/libs/wire-api-federation/src/Wire/API/Federation/Client.hs b/libs/wire-api-federation/src/Wire/API/Federation/Client.hs
index 7b6a601156a..a2f3f1896fa 100644
--- a/libs/wire-api-federation/src/Wire/API/Federation/Client.hs
+++ b/libs/wire-api-federation/src/Wire/API/Federation/Client.hs
@@ -38,6 +38,7 @@ import Control.Monad.Codensity
 import Control.Monad.Except
 import Control.Monad.Trans.Maybe
 import qualified Data.Aeson as Aeson
+import Data.Bifunctor (first)
 import qualified Data.ByteString as BS
 import Data.ByteString.Builder
 import Data.ByteString.Conversion (toByteString')
@@ -112,8 +113,7 @@ liftCodensity :: Codensity IO a -> FederatorClient c a
 liftCodensity = FederatorClient . lift . lift . lift
 
 headersFromTable :: HTTP2.HeaderTable -> [HTTP.Header]
-headersFromTable (headerList, _) = flip map headerList $ \(token, headerValue) ->
-  (HTTP2.tokenKey token, headerValue)
+headersFromTable (headerList, _) = flip map headerList $ first HTTP2.tokenKey
 
 connectSocket :: ByteString -> Int -> IO NS.Socket
 connectSocket hostname port =
@@ -130,7 +130,7 @@ performHTTP2Request ::
 performHTTP2Request mtlsConfig req hostname port = try $ do
   withHTTP2Request mtlsConfig req hostname port $ \resp -> do
     b <-
-      fmap (either (const mempty) id)
+      fmap (fromRight mempty)
         . runExceptT
         . runSourceT
         . responseBody
@@ -199,12 +199,11 @@ instance KnownComponent c => RunStreamingClient (FederatorClient c) where
   withStreamingRequest = withHTTP2StreamingRequest HTTP.statusIsSuccessful
 
 streamingResponseStrictBody :: StreamingResponse -> IO Builder
-streamingResponseStrictBody resp =
+streamingResponseStrictBody =
   fmap (either stringUtf8 (foldMap byteString))
     . runExceptT
     . runSourceT
     . responseBody
-    $ resp
 
 -- Perform a streaming request to the local federator.
 withHTTP2StreamingRequest ::
@@ -225,13 +224,11 @@ withHTTP2StreamingRequest successfulStatus req handleResponse = do
   let path = baseUrlPath <> requestPath req
 
   body <- do
-    body <- case requestBody req of
+    case requestBody req of
       Just (RequestBodyLBS lbs, _) -> pure lbs
       Just (RequestBodyBS bs, _) -> pure (LBS.fromStrict bs)
-      Just (RequestBodySource _, _) ->
-        throwError FederatorClientStreamingNotSupported
+      Just (RequestBodySource _, _) -> throwError FederatorClientStreamingNotSupported
       Nothing -> pure mempty
-    pure body
   let req' =
         HTTP2.requestBuilder
           (requestMethod req)
@@ -240,7 +237,7 @@ withHTTP2StreamingRequest successfulStatus req handleResponse = do
           (lazyByteString body)
   let Endpoint (Text.encodeUtf8 -> hostname) (fromIntegral -> port) = ceFederator env
   resp <-
-    (either throwError pure =<<) . liftCodensity $
+    either throwError pure <=< liftCodensity $
       Codensity $ \k ->
         E.catch
           (withHTTP2Request Nothing req' hostname port (k . Right))
@@ -326,9 +323,11 @@ runVersionedFederatorClientToCodensity ::
   ExceptT FederatorClientError (Codensity IO) a
 runVersionedFederatorClientToCodensity env =
   flip runReaderT env
-    . (maybe (E.throw FederatorClientVersionMismatch) pure =<<)
+    . unmaybe
     . runMaybeT
     . unFederatorClient
+  where
+    unmaybe = (maybe (E.throw FederatorClientVersionMismatch) pure =<<)
 
 versionNegotiation :: FederatorClient 'Brig Version
 versionNegotiation =
diff --git a/libs/wire-api/src/Wire/API/Routes/Public/Brig.hs b/libs/wire-api/src/Wire/API/Routes/Public/Brig.hs
index fc590359120..f424a110781 100644
--- a/libs/wire-api/src/Wire/API/Routes/Public/Brig.hs
+++ b/libs/wire-api/src/Wire/API/Routes/Public/Brig.hs
@@ -803,30 +803,28 @@ type MLSKeyPackageAPI =
                :> ReqBody '[JSON] KeyPackageUpload
                :> MultiVerb 'POST '[JSON, MLS] '[RespondEmpty 201 "Key packages uploaded"] ()
            )
-           :<|> ( Named
-                    "mls-key-packages-claim"
-                    ( "claim"
-                        :> Summary "Claim one key package for each client of the given user"
-                        :> QualifiedCaptureUserId "user"
-                        :> QueryParam'
-                             [ Optional,
-                               Strict,
-                               Description "Do not claim a key package for the given own client"
-                             ]
-                             "skip_own"
-                             ClientId
-                        :> MultiVerb1 'POST '[JSON] (Respond 200 "Claimed key packages" KeyPackageBundle)
-                    )
-                )
-           :<|> ( Named
-                    "mls-key-packages-count"
-                    ( "self"
-                        :> CaptureClientId "client"
-                        :> "count"
-                        :> Summary "Return the number of unused key packages for the given client"
-                        :> MultiVerb1 'GET '[JSON] (Respond 200 "Number of key packages" KeyPackageCount)
-                    )
-                )
+           :<|> Named
+                  "mls-key-packages-claim"
+                  ( "claim"
+                      :> Summary "Claim one key package for each client of the given user"
+                      :> QualifiedCaptureUserId "user"
+                      :> QueryParam'
+                           [ Optional,
+                             Strict,
+                             Description "Do not claim a key package for the given own client"
+                           ]
+                           "skip_own"
+                           ClientId
+                      :> MultiVerb1 'POST '[JSON] (Respond 200 "Claimed key packages" KeyPackageBundle)
+                  )
+           :<|> Named
+                  "mls-key-packages-count"
+                  ( "self"
+                      :> CaptureClientId "client"
+                      :> "count"
+                      :> Summary "Return the number of unused key packages for the given client"
+                      :> MultiVerb1 'GET '[JSON] (Respond 200 "Number of key packages" KeyPackageCount)
+                  )
        )
 
 type MLSAPI = LiftNamed (ZLocalUser :> "mls" :> MLSKeyPackageAPI)
diff --git a/libs/zauth/main/Main.hs b/libs/zauth/main/Main.hs
index 61e00e41933..e09be731bfc 100644
--- a/libs/zauth/main/Main.hs
+++ b/libs/zauth/main/Main.hs
@@ -102,14 +102,14 @@ go CreateAccess o = do
 go CreateBot o = do
   when (length (o ^. dat) /= 3) $
     error "invalid --data, must have 3 elements"
-  let p = uuid $ (o ^. dat) !! 0
+  let p = uuid $ head (o ^. dat)
       b = uuid $ (o ^. dat) !! 1
       c = uuid $ (o ^. dat) !! 2
   runCreate' o $ toByteString <$> botToken p b c
 go CreateProvider o = do
   when (length (o ^. dat) /= 1) $
     error "missing --data"
-  let p = uuid $ (o ^. dat) !! 0
+  let p = uuid $ head (o ^. dat)
   runCreate' o $ toByteString <$> providerToken (o ^. dur) p
 go GenKeyPair _ = do
   (p, s) <- newKeyPair
@@ -123,7 +123,7 @@ uuid :: ByteString -> UUID
 uuid s = fromMaybe (error $ "Invalid UUID: " ++ show s) $ fromASCIIBytes s
 
 check' :: ToByteString a => ByteString -> Token a -> IO ()
-check' k t = exceptT (\e -> putStrLn e >> exitFailure) (const $ return ()) $ do
+check' k t = exceptT (\e -> putStrLn e >> exitFailure) (const $ pure ()) $ do
   p <- hoistEither $ PublicKey <$> decode k
   e <- liftIO $ runValidate (V.mkEnv p (replicate (t ^. header . key) p)) (check t)
   hoistEither $ fmapL show e
@@ -181,14 +181,14 @@ options =
           <> help "token data"
     toMode =
       readerAsk >>= \s -> case s of
-        "create-user" -> return CreateUser
-        "create-session" -> return CreateSession
-        "create-access" -> return CreateAccess
-        "create-bot" -> return CreateBot
-        "create-provider" -> return CreateProvider
-        "verify-user" -> return VerifyUser
-        "verify-access" -> return VerifyAccess
-        "verify-bot" -> return VerifyBot
-        "verify-provider" -> return VerifyProvider
-        "gen-keypair" -> return GenKeyPair
+        "create-user" -> pure CreateUser
+        "create-session" -> pure CreateSession
+        "create-access" -> pure CreateAccess
+        "create-bot" -> pure CreateBot
+        "create-provider" -> pure CreateProvider
+        "verify-user" -> pure VerifyUser
+        "verify-access" -> pure VerifyAccess
+        "verify-bot" -> pure VerifyBot
+        "verify-provider" -> pure VerifyProvider
+        "gen-keypair" -> pure GenKeyPair
         other -> readerError $ "invalid mode: " <> other
diff --git a/libs/zauth/src/Data/ZAuth/Creation.hs b/libs/zauth/src/Data/ZAuth/Creation.hs
index 003dd4c2598..179317a7263 100644
--- a/libs/zauth/src/Data/ZAuth/Creation.hs
+++ b/libs/zauth/src/Data/ZAuth/Creation.hs
@@ -156,7 +156,7 @@ newToken ti ty ta a = do
   k <- Create $ asks keyIdx
   let h = mkHeader tokenVersion k (floor ti) ty ta
   s <- signToken h a
-  return $ mkToken s h a
+  pure $ mkToken s h a
 
 -----------------------------------------------------------------------------
 -- Internal
diff --git a/libs/zauth/src/Data/ZAuth/Token.hs b/libs/zauth/src/Data/ZAuth/Token.hs
index 52ea198c456..a4319822dcd 100644
--- a/libs/zauth/src/Data/ZAuth/Token.hs
+++ b/libs/zauth/src/Data/ZAuth/Token.hs
@@ -189,42 +189,42 @@ instance FromByteString (Token Access) where
     takeLazyByteString >>= \b ->
       case readToken A readAccessBody b of
         Nothing -> fail "Invalid access token"
-        Just t -> return t
+        Just t -> pure t
 
 instance FromByteString (Token User) where
   parser =
     takeLazyByteString >>= \b ->
       case readToken U readUserBody b of
         Nothing -> fail "Invalid user token"
-        Just t -> return t
+        Just t -> pure t
 
 instance FromByteString (Token Bot) where
   parser =
     takeLazyByteString >>= \b ->
       case readToken B readBotBody b of
         Nothing -> fail "Invalid bot token"
-        Just t -> return t
+        Just t -> pure t
 
 instance FromByteString (Token Provider) where
   parser =
     takeLazyByteString >>= \b ->
       case readToken P readProviderBody b of
         Nothing -> fail "Invalid provider token"
-        Just t -> return t
+        Just t -> pure t
 
 instance FromByteString (Token LegalHoldAccess) where
   parser =
     takeLazyByteString >>= \b ->
       case readToken LA readLegalHoldAccessBody b of
         Nothing -> fail "Invalid access token"
-        Just t -> return t
+        Just t -> pure t
 
 instance FromByteString (Token LegalHoldUser) where
   parser =
     takeLazyByteString >>= \b ->
       case readToken LU readLegalHoldUserBody b of
         Nothing -> fail "Invalid user token"
-        Just t -> return t
+        Just t -> pure t
 
 instance ToByteString a => ToByteString (Token a) where
   builder = writeToken
@@ -236,7 +236,7 @@ mkToken :: Signature -> Header -> a -> Token a
 mkToken = Token
 
 mkHeader :: Int -> Int -> Integer -> Type -> Maybe Tag -> Header
-mkHeader v k d t g = Header v k d t g
+mkHeader = Header
 
 mkAccess :: UUID -> Word64 -> Access
 mkAccess = Access
diff --git a/libs/zauth/src/Data/ZAuth/Validation.hs b/libs/zauth/src/Data/ZAuth/Validation.hs
index 6bafd2e87ea..97c2a96836e 100644
--- a/libs/zauth/src/Data/ZAuth/Validation.hs
+++ b/libs/zauth/src/Data/ZAuth/Validation.hs
@@ -104,13 +104,13 @@ validate Nothing Nothing = throwError Invalid
 validate (Just _) Nothing = throwError Invalid
 validate Nothing (Just t) = validateAccess t
 validate (Just c) (Just t) = do
-  u <- maybe (throwError Invalid) return (fromByteString c)
-  a <- maybe (throwError Invalid) return (fromByteString t)
+  u <- maybe (throwError Invalid) pure (fromByteString c)
+  a <- maybe (throwError Invalid) pure (fromByteString t)
   void $ check u
   void $ check a
   unless (u ^. body . user == a ^. body . userId) $
     throwError Invalid
-  return a
+  pure a
 
 check :: ToByteString a => Token a -> Validate (Token a)
 check t = do
@@ -124,11 +124,11 @@ check t = do
     throwError Falsified
   isExpired <-
     if t ^. header . time == -1
-      then return False
+      then pure False
       else (t ^. header . time <) <$> now
   when isExpired $
     throwError Expired
-  return t
+  pure t
 
 now :: (Functor m, MonadIO m) => m Integer
 now = floor <$> liftIO getPOSIXTime
diff --git a/libs/zauth/test/Arbitraries.hs b/libs/zauth/test/Arbitraries.hs
index bb17ae9b58d..16d2f9c8d69 100644
--- a/libs/zauth/test/Arbitraries.hs
+++ b/libs/zauth/test/Arbitraries.hs
@@ -74,7 +74,7 @@ instance Arbitrary LegalHoldUser where
   arbitrary = mkLegalHoldUser <$> arbitrary <*> arbitrary
 
 instance Arbitrary ByteString where
-  arbitrary = fromString <$> arbitrary `suchThat` (not . any (== '.'))
+  arbitrary = fromString <$> arbitrary `suchThat` notElem '.'
 
 instance Arbitrary Signature where
   arbitrary = Signature <$> arbitrary
@@ -83,7 +83,7 @@ instance Arbitrary Type where
   arbitrary = elements [A, U, LA, LU]
 
 instance Arbitrary Tag where
-  arbitrary = return S
+  arbitrary = pure S
 
 instance Bounded UUID where
   minBound = nil
diff --git a/libs/zauth/test/ZAuth.hs b/libs/zauth/test/ZAuth.hs
index 703cbd69b5a..1b6fd4d518f 100644
--- a/libs/zauth/test/ZAuth.hs
+++ b/libs/zauth/test/ZAuth.hs
@@ -42,7 +42,7 @@ tests = do
   (p3, s3) <- newKeyPair
   z <- C.mkEnv s1 [s2, s3]
   let v = V.mkEnv p1 [p2, p3]
-  return $
+  pure $
     testGroup
       "ZAuth"
       [ testGroup
@@ -69,10 +69,10 @@ defDuration :: Integer
 defDuration = 1
 
 testUserIsNotLegalHoldUser :: Token LegalHoldUser -> Bool
-testUserIsNotLegalHoldUser t = fromByteString @(Token User) (toByteString' t) == Nothing
+testUserIsNotLegalHoldUser t = isNothing (fromByteString @(Token User) (toByteString' t))
 
 testUserIsNotLegalHoldUser' :: Token User -> Bool
-testUserIsNotLegalHoldUser' t = fromByteString @(Token LegalHoldUser) (toByteString' t) == Nothing
+testUserIsNotLegalHoldUser' t = isNothing (fromByteString @(Token LegalHoldUser) (toByteString' t))
 
 testDecEncAccessToken :: Token Access -> Bool
 testDecEncAccessToken t = fromByteString (toByteString' t) == Just t
@@ -117,8 +117,8 @@ testSignAndVerify p = do
 testRandDevIds :: Create ()
 testRandDevIds = do
   u <- liftIO nextRandom
-  t1 <- (view body) <$> accessToken1 defDuration u
-  t2 <- (view body) <$> accessToken1 defDuration u
+  t1 <- view body <$> accessToken1 defDuration u
+  t2 <- view body <$> accessToken1 defDuration u
   liftIO $ assertBool "unexpected: Same device ID." (t1 ^. connection /= t2 ^. connection)
 
 -- Helpers: