diff --git a/lib/models/ui/comment_details.dart b/lib/models/ui/comment_details.dart
index f68fa7fd..9f496df4 100644
--- a/lib/models/ui/comment_details.dart
+++ b/lib/models/ui/comment_details.dart
@@ -1,12 +1,16 @@
 import "package:flutter/foundation.dart";
 import "package:proxima/models/database/comment/comment_data.dart";
 import "package:proxima/models/database/user/user_firestore.dart";
+import "package:proxima/models/database/user/user_id_firestore.dart";
 
+/// This class contains all the details of a comment
+/// that are needed to display it in the UI.
 @immutable
 class CommentDetails {
   final String content;
   final String ownerDisplayName;
   final String ownerUsername;
+  final UserIdFirestore ownerUserID;
   final int ownerCentauriPoints;
   final DateTime publicationDate;
 
@@ -14,6 +18,7 @@ class CommentDetails {
     required this.content,
     required this.ownerDisplayName,
     required this.ownerUsername,
+    required this.ownerUserID,
     required this.ownerCentauriPoints,
     required this.publicationDate,
   });
@@ -26,6 +31,7 @@ class CommentDetails {
         other.content == content &&
         other.ownerDisplayName == ownerDisplayName &&
         other.ownerUsername == ownerUsername &&
+        other.ownerUserID == ownerUserID &&
         other.ownerCentauriPoints == ownerCentauriPoints &&
         other.publicationDate == publicationDate;
   }
@@ -36,6 +42,7 @@ class CommentDetails {
       content,
       ownerDisplayName,
       ownerUsername,
+      ownerUserID,
       ownerCentauriPoints,
       publicationDate,
     );
@@ -53,6 +60,7 @@ class CommentDetails {
       content: commentData.content,
       ownerDisplayName: ownerData.displayName,
       ownerUsername: ownerData.username,
+      ownerUserID: owner.uid,
       ownerCentauriPoints: ownerData.centauriPoints,
       publicationDate: DateTime.fromMillisecondsSinceEpoch(
         commentData.publicationTime.millisecondsSinceEpoch,
diff --git a/lib/models/ui/post_details.dart b/lib/models/ui/post_details.dart
index 8b2e2ac8..80d27906 100644
--- a/lib/models/ui/post_details.dart
+++ b/lib/models/ui/post_details.dart
@@ -3,6 +3,7 @@ import "package:geoflutterfire_plus/geoflutterfire_plus.dart";
 import "package:proxima/models/database/post/post_firestore.dart";
 import "package:proxima/models/database/post/post_id_firestore.dart";
 import "package:proxima/models/database/user/user_firestore.dart";
+import "package:proxima/models/database/user/user_id_firestore.dart";
 
 @immutable
 
@@ -15,6 +16,7 @@ class PostDetails {
   final int commentNumber;
   final String ownerDisplayName;
   final String ownerUsername;
+  final UserIdFirestore ownerUserID;
   final int ownerCentauriPoints;
   final DateTime publicationDate;
   final int distance; // in meters
@@ -28,6 +30,7 @@ class PostDetails {
     required this.commentNumber,
     required this.ownerDisplayName,
     required this.ownerUsername,
+    required this.ownerUserID,
     required this.ownerCentauriPoints,
     required this.publicationDate,
     required this.distance,
@@ -46,6 +49,7 @@ class PostDetails {
         other.commentNumber == commentNumber &&
         other.ownerDisplayName == ownerDisplayName &&
         other.ownerUsername == ownerUsername &&
+        other.ownerUserID == ownerUserID &&
         other.ownerCentauriPoints == ownerCentauriPoints &&
         other.publicationDate == publicationDate &&
         other.distance == distance &&
@@ -62,6 +66,7 @@ class PostDetails {
       commentNumber,
       ownerDisplayName,
       ownerUsername,
+      ownerUserID,
       ownerCentauriPoints,
       publicationDate,
       distance,
@@ -86,6 +91,7 @@ class PostDetails {
       commentNumber: postFirestore.data.commentCount,
       ownerDisplayName: userFirestore.data.displayName,
       ownerUsername: userFirestore.data.username,
+      ownerUserID: userFirestore.uid,
       ownerCentauriPoints: userFirestore.data.centauriPoints,
       publicationDate: postFirestore.data.publicationTime.toDate(),
       distance: (geoFirePoint.distanceBetweenInKm(
diff --git a/lib/models/ui/ranking/ranking_element_details.dart b/lib/models/ui/ranking/ranking_element_details.dart
index 5ea5fcd3..05038fd2 100644
--- a/lib/models/ui/ranking/ranking_element_details.dart
+++ b/lib/models/ui/ranking/ranking_element_details.dart
@@ -1,4 +1,5 @@
 import "package:flutter/foundation.dart";
+import "package:proxima/models/database/user/user_id_firestore.dart";
 
 /// A class that stores data for each ranking UI element.
 /// The [userRank] is nullable to allow the current user to not have a rank.
@@ -7,6 +8,7 @@ class RankingElementDetails {
   const RankingElementDetails({
     required this.userDisplayName,
     required this.userUserName,
+    required this.userID,
     required this.centauriPoints,
     required this.userRank,
   });
@@ -17,6 +19,9 @@ class RankingElementDetails {
   /// Username of the user.
   final String userUserName;
 
+  /// ID of the user.
+  final UserIdFirestore userID;
+
   /// Centauri points of the user.
   final int centauriPoints;
 
@@ -30,6 +35,7 @@ class RankingElementDetails {
     return other is RankingElementDetails &&
         other.userDisplayName == userDisplayName &&
         other.userUserName == userUserName &&
+        other.userID == userID &&
         other.centauriPoints == centauriPoints &&
         other.userRank == userRank;
   }
@@ -38,6 +44,7 @@ class RankingElementDetails {
   int get hashCode => Object.hash(
         userDisplayName,
         userUserName,
+        userID,
         centauriPoints,
         userRank,
       );
diff --git a/lib/models/ui/user_avatar_details.dart b/lib/models/ui/user_avatar_details.dart
index 14b24ade..3f182fcb 100644
--- a/lib/models/ui/user_avatar_details.dart
+++ b/lib/models/ui/user_avatar_details.dart
@@ -1,27 +1,29 @@
 import "package:flutter/foundation.dart";
-import "package:proxima/models/database/user/user_data.dart";
+import "package:proxima/models/database/user/user_firestore.dart";
 
 /// A class that stores data for a user avatar UI.
 @immutable
 class UserAvatarDetails {
   final String displayName;
-  final int? userCentauriPoints;
+  final int? centauriPoints;
 
   /// Creates a [UserAvatarDetails] object.
   /// [displayName] is the user's display name, of which
   /// the first letter is displayed on the avatar.
-  /// [userCentauriPoints] is the user's centauri points,
-  /// which is used to color the avatar background.
+  /// [centauriPoints] is the user's centauri points.
+  /// The [centauriPoints] parameter can be null, which is useful for loading states.
   const UserAvatarDetails({
     required this.displayName,
-    required this.userCentauriPoints,
+    required this.centauriPoints,
   });
 
-  /// Converts a [UserData] object, [userData], to a [UserAvatarDetails] object.
-  factory UserAvatarDetails.fromUserData(UserData userData) {
+  /// Converts a [UserFirestore] object, [user], to a [UserAvatarDetails] object.
+  factory UserAvatarDetails.fromUser(
+    UserFirestore user,
+  ) {
     return UserAvatarDetails(
-      displayName: userData.displayName,
-      userCentauriPoints: userData.centauriPoints,
+      displayName: user.data.displayName,
+      centauriPoints: user.data.centauriPoints,
     );
   }
 
@@ -29,14 +31,14 @@ class UserAvatarDetails {
   bool operator ==(Object other) {
     return other is UserAvatarDetails &&
         other.displayName == displayName &&
-        other.userCentauriPoints == userCentauriPoints;
+        other.centauriPoints == centauriPoints;
   }
 
   @override
   int get hashCode {
     return Object.hash(
       displayName,
-      userCentauriPoints,
+      centauriPoints,
     );
   }
 }
diff --git a/lib/utils/user_avatar_color.dart b/lib/utils/user_avatar_color.dart
new file mode 100644
index 00000000..3ffd5a36
--- /dev/null
+++ b/lib/utils/user_avatar_color.dart
@@ -0,0 +1,46 @@
+import "package:flutter/material.dart";
+import "package:proxima/models/ui/linear_segmented_hsv_colormap.dart";
+import "package:proxima/services/database/challenge_repository_service.dart";
+
+/// Stops for the colormap used to color the user's avatar based on their centauri points.
+/// The stops are defined as the number of challenges completed.
+const _challengesStops = [
+  // sqrt(10) ~= 3, which is the approximate step between each stop
+  0,
+  10, // ~ 3 days of daily challenge
+  30,
+  100,
+  300, // ~ 3 months of daily challenge
+  1000,
+  3000, // ~ 3 years of daily challenge
+  10000,
+];
+
+/// Color used when the user's centauri points are null.
+const loadingUserAvatarColor = Colors.transparent;
+
+/// Converts some amount of [centauriPoints] to a color, based on a uniform
+/// [LinearSegmentedHSVColormap] (defined by _challengesStop). [brightness]
+/// defines the value and saturation of the colormap.
+/// If [centauriPoints] is null, the color is transparent.
+Color centauriToUserAvatarColor(int? centauriPoints, Brightness brightness) {
+  if (centauriPoints == null) return loadingUserAvatarColor;
+
+  final hsvValue = switch (brightness) {
+    Brightness.light => 0.9,
+    Brightness.dark => 0.5,
+  };
+  final hsvSaturation = switch (brightness) {
+    Brightness.light => 0.4,
+    Brightness.dark => 0.8,
+  };
+
+  const chalReward = ChallengeRepositoryService.soloChallengeReward;
+  final colorMap = LinearSegmentedHSVColormap.uniform(
+    _challengesStops.map((nChallenges) => nChallenges * chalReward).toList(),
+    value: hsvValue,
+    saturation: hsvSaturation,
+  );
+
+  return colorMap(centauriPoints).toColor();
+}
diff --git a/lib/viewmodels/challenge_view_model.dart b/lib/viewmodels/challenge_view_model.dart
index 6663f171..497eb5c7 100644
--- a/lib/viewmodels/challenge_view_model.dart
+++ b/lib/viewmodels/challenge_view_model.dart
@@ -5,6 +5,7 @@ import "package:proxima/models/ui/challenge_details.dart";
 import "package:proxima/services/database/challenge_repository_service.dart";
 import "package:proxima/services/database/post_repository_service.dart";
 import "package:proxima/services/sensors/geolocation_service.dart";
+import "package:proxima/viewmodels/dynamic_user_avatar_view_model.dart";
 import "package:proxima/viewmodels/login_view_model.dart";
 import "package:proxima/viewmodels/map/map_pin_view_model.dart";
 
@@ -98,6 +99,13 @@ class ChallengeViewModel
 
       // Refresh the map pins after challenge completion
       ref.read(mapPinViewModelProvider.notifier).refresh();
+
+      // Refresh the user centauri points after challenge completion
+      // Note: null is the current user id as represented in dynamicUserAvatarViewModelProvider
+      // So we have to refresh both [currentUser] and the null user
+      for (final user in [null, currentUser]) {
+        ref.read(dynamicUserAvatarViewModelProvider(user).notifier).refresh();
+      }
     }
 
     return pointsAwarded;
diff --git a/lib/viewmodels/comments_view_model.dart b/lib/viewmodels/comments_view_model.dart
index aa05babd..9b2a67c8 100644
--- a/lib/viewmodels/comments_view_model.dart
+++ b/lib/viewmodels/comments_view_model.dart
@@ -6,6 +6,7 @@ import "package:proxima/models/database/post/post_id_firestore.dart";
 import "package:proxima/models/ui/comment_details.dart";
 import "package:proxima/services/database/comment/comment_repository_service.dart";
 import "package:proxima/services/database/user_repository_service.dart";
+import "package:proxima/viewmodels/post_comment_count_view_model.dart";
 
 /// This view model is used to fetch the comments of a post.
 /// It fetches the comments under the post with the id [arg] and returns
@@ -21,6 +22,9 @@ class CommentsViewModel extends AutoDisposeFamilyAsyncNotifier<
 
     final commentsFirestore = await commentRepository.getPostComments(arg);
 
+    // Update the post comment count
+    ref.read(postCommentCountProvider(arg).notifier).refresh();
+
     final commentOwnersId =
         commentsFirestore.map((comment) => comment.data.ownerId).toSet();
 
diff --git a/lib/viewmodels/dynamic_user_avatar_view_model.dart b/lib/viewmodels/dynamic_user_avatar_view_model.dart
index d42e2be4..63c8298a 100644
--- a/lib/viewmodels/dynamic_user_avatar_view_model.dart
+++ b/lib/viewmodels/dynamic_user_avatar_view_model.dart
@@ -1,87 +1,53 @@
 import "dart:async";
 
-import "package:flutter/material.dart";
 import "package:hooks_riverpod/hooks_riverpod.dart";
 import "package:proxima/models/database/user/user_firestore.dart";
 import "package:proxima/models/database/user/user_id_firestore.dart";
-import "package:proxima/models/ui/linear_segmented_hsv_colormap.dart";
 import "package:proxima/models/ui/user_avatar_details.dart";
-import "package:proxima/services/database/challenge_repository_service.dart";
 import "package:proxima/services/database/user_repository_service.dart";
 import "package:proxima/viewmodels/login_view_model.dart";
 
+// TODO: Remove the fact that the current user is "null" and accept a non-nullable user id.
 /// View model for the dynamic user avatar.
-/// This view model is used to fetch the user's display name given its id.
-/// If the id is null, the current user's display name is fetched.
+/// This view model is used to fetch the user's display name and centauri points
+/// given its id. If the id is null, the current user's information is fetched.
 class DynamicUserAvatarViewModel extends AutoDisposeFamilyAsyncNotifier<
     UserAvatarDetails, UserIdFirestore?> {
   DynamicUserAvatarViewModel();
 
-  /// Stops for the colormap used to color the user's avatar based on their centauri points.
-  /// The stops are defined as the number of challenges completed.
-  static const _challengesStops = [
-    // sqrt(10) ~= 3, which is the approximate step between each stop
-    0,
-    10, // ~ 3 days of daily challenge
-    30,
-    100,
-    300, // ~ 3 months of daily challenge
-    1000,
-    3000, // ~ 3 years of daily challenge
-    10000,
-  ];
-
-  /// Converts some amount of [centauriPoints] to a color, based on a uniform
-  /// [LinearSegmentedHSVColormap] (defined by _challengesStop). [brightness]
-  /// defines the value and saturation of the colormap.
-  /// If [centauriPoints] is null, the color is transparent.
-  static Color centauriToColor(int? centauriPoints, Brightness brightness) {
-    if (centauriPoints == null) return Colors.transparent;
-
-    final hsvValue = switch (brightness) {
-      Brightness.light => 0.9,
-      Brightness.dark => 0.5,
-    };
-    final hsvSaturation = switch (brightness) {
-      Brightness.light => 0.4,
-      Brightness.dark => 0.8,
-    };
-
-    const chalReward = ChallengeRepositoryService.soloChallengeReward;
-    final colorMap = LinearSegmentedHSVColormap.uniform(
-      _challengesStops.map((nChallenges) => nChallenges * chalReward).toList(),
-      value: hsvValue,
-      saturation: hsvSaturation,
-    );
-
-    return colorMap(centauriPoints).toColor();
-  }
-
   @override
   Future<UserAvatarDetails> build(UserIdFirestore? arg) async {
-    final userID = arg;
     final currentUID = ref.watch(loggedInUserIdProvider);
     final userDataBase = ref.watch(userRepositoryServiceProvider);
 
     late final UserFirestore user;
+    late final UserIdFirestore userID;
 
-    if (userID == null) {
+    if (arg == null) {
       if (currentUID == null) {
         throw Exception("User is not logged in.");
       }
-
-      user = await userDataBase.getUser(currentUID);
+      userID = currentUID;
     } else {
-      user = await userDataBase.getUser(userID);
+      userID = arg;
     }
 
-    return UserAvatarDetails.fromUserData(user.data);
+    user = await userDataBase.getUser(userID);
+
+    return UserAvatarDetails.fromUser(user);
+  }
+
+  /// Refresh the user's information.
+  Future<void> refresh() async {
+    state = const AsyncValue.loading();
+
+    state = await AsyncValue.guard(() => build(arg));
   }
 }
 
 //TODO: Extend to fetch the user's avatar image.
-/// Flexible provider allowing to retrieve the user's display name given its id.
-/// If the id is null, the current user's display name is fetched.
+/// Flexible provider allowing to retrieve the user's display name and centauri points
+/// given its id. If the id is null, the current user's information is fetched.
 final dynamicUserAvatarViewModelProvider = AsyncNotifierProvider.autoDispose
     .family<DynamicUserAvatarViewModel, UserAvatarDetails, UserIdFirestore?>(
   () => DynamicUserAvatarViewModel(),
diff --git a/lib/viewmodels/post_comment_count_view_model.dart b/lib/viewmodels/post_comment_count_view_model.dart
new file mode 100644
index 00000000..85ee31ad
--- /dev/null
+++ b/lib/viewmodels/post_comment_count_view_model.dart
@@ -0,0 +1,28 @@
+import "package:hooks_riverpod/hooks_riverpod.dart";
+import "package:proxima/models/database/post/post_id_firestore.dart";
+import "package:proxima/services/database/post_repository_service.dart";
+
+/// This view model is used to keep in memory the number of comments of a post.
+/// It is refreshed every time the post comment list is refreshed, to stay consistent
+/// with it. It is also refreshed when a comment is deleted.
+/// This cannot be auto-dispose because, otherwise, it might get unmounted in the middle
+/// of its refresh method. See https://github.com/rrousselGit/riverpod/discussions/2502.
+class PostCommentCountViewModel
+    extends FamilyAsyncNotifier<int, PostIdFirestore> {
+  @override
+  Future<int> build(PostIdFirestore arg) async {
+    final postRepo = ref.watch(postRepositoryServiceProvider);
+    final post = await postRepo.getPost(arg);
+    return post.data.commentCount;
+  }
+
+  Future<void> refresh() async {
+    state = const AsyncValue.loading();
+    state = await AsyncValue.guard(() => build(arg));
+  }
+}
+
+final postCommentCountProvider = AsyncNotifierProvider.family<
+    PostCommentCountViewModel, int, PostIdFirestore>(
+  () => PostCommentCountViewModel(),
+);
diff --git a/lib/viewmodels/user_comments_view_model.dart b/lib/viewmodels/user_comments_view_model.dart
index 066655d4..8b0227e3 100644
--- a/lib/viewmodels/user_comments_view_model.dart
+++ b/lib/viewmodels/user_comments_view_model.dart
@@ -5,6 +5,7 @@ import "package:proxima/models/database/post/post_id_firestore.dart";
 import "package:proxima/models/ui/user_comment_details.dart";
 import "package:proxima/services/database/comment/comment_repository_service.dart";
 import "package:proxima/viewmodels/login_view_model.dart";
+import "package:proxima/viewmodels/post_comment_count_view_model.dart";
 import "package:proxima/viewmodels/posts_feed_view_model.dart";
 
 typedef UserCommentsState = List<UserCommentDetails>;
@@ -53,6 +54,8 @@ class UserCommentViewModel extends AutoDisposeAsyncNotifier<UserCommentsState> {
     // Refresh the home feed after comment deletion, that way the comment
     // count will be updated
     ref.read(postsFeedViewModelProvider.notifier).refresh();
+    // Also update the comment count for the post
+    ref.read(postCommentCountProvider(postId).notifier).refresh();
   }
 
   /// Refresh the list of posts
diff --git a/lib/viewmodels/users_ranking_view_model.dart b/lib/viewmodels/users_ranking_view_model.dart
index 85ad99c7..5ad10edc 100644
--- a/lib/viewmodels/users_ranking_view_model.dart
+++ b/lib/viewmodels/users_ranking_view_model.dart
@@ -3,6 +3,7 @@ import "package:hooks_riverpod/hooks_riverpod.dart";
 import "package:proxima/models/ui/ranking/ranking_details.dart";
 import "package:proxima/models/ui/ranking/ranking_element_details.dart";
 import "package:proxima/services/database/user_repository_service.dart";
+import "package:proxima/viewmodels/dynamic_user_avatar_view_model.dart";
 import "package:proxima/viewmodels/login_view_model.dart";
 
 /// Provides a refreshable async list of users that are sorted by
@@ -37,6 +38,7 @@ class UsersRankingViewModel extends AutoDisposeAsyncNotifier<RankingDetails> {
       final userRankingDetails = RankingElementDetails(
         userDisplayName: userData.displayName,
         userUserName: userData.username,
+        userID: user.uid,
         centauriPoints: userData.centauriPoints,
         userRank: userRank,
       );
@@ -44,7 +46,8 @@ class UsersRankingViewModel extends AutoDisposeAsyncNotifier<RankingDetails> {
       return userRankingDetails;
     }).toList();
 
-    final currentUserData = futures.$2.data;
+    final currentUser = futures.$2;
+    final currentUserData = currentUser.data;
 
     // If the current user is in the leaderboard, also provide its rank
     final currentUserRank = topUsers.firstWhereOrNull(
@@ -54,6 +57,7 @@ class UsersRankingViewModel extends AutoDisposeAsyncNotifier<RankingDetails> {
     final currentUserRankingDetails = RankingElementDetails(
       userDisplayName: currentUserData.displayName,
       userUserName: currentUserData.username,
+      userID: currentUser.uid,
       centauriPoints: currentUserData.centauriPoints,
       userRank: currentUserRank?.userRank,
     );
@@ -64,6 +68,19 @@ class UsersRankingViewModel extends AutoDisposeAsyncNotifier<RankingDetails> {
       userRankElementDetails: currentUserRankingDetails,
     );
 
+    // Get the list of user ids to refresh, and refresh the avatars.
+    // Note that we also need to refresh the null user avatar
+    // which represents the current user.
+    final userIds =
+        ([currentUser, null] + topUsersFromDb).map((user) => user?.uid);
+
+    for (final userId in userIds) {
+      ref
+          .read(
+            dynamicUserAvatarViewModelProvider(userId).notifier,
+          )
+          .refresh();
+    }
     return state;
   }
 
diff --git a/lib/views/components/content/user_avatar/dynamic_user_avatar.dart b/lib/views/components/content/user_avatar/dynamic_user_avatar.dart
index 8b4580d5..27649958 100644
--- a/lib/views/components/content/user_avatar/dynamic_user_avatar.dart
+++ b/lib/views/components/content/user_avatar/dynamic_user_avatar.dart
@@ -13,7 +13,7 @@ import "package:proxima/views/components/content/user_avatar/user_avatar.dart";
 class DynamicUserAvatar extends ConsumerWidget {
   static const _loadingDetails = UserAvatarDetails(
     displayName: "",
-    userCentauriPoints: null,
+    centauriPoints: null,
   );
 
   final UserIdFirestore? uid;
diff --git a/lib/views/components/content/user_avatar/user_avatar.dart b/lib/views/components/content/user_avatar/user_avatar.dart
index efbc4949..937e3dc4 100644
--- a/lib/views/components/content/user_avatar/user_avatar.dart
+++ b/lib/views/components/content/user_avatar/user_avatar.dart
@@ -1,12 +1,13 @@
 import "package:flutter/material.dart";
+import "package:hooks_riverpod/hooks_riverpod.dart";
 import "package:proxima/models/ui/user_avatar_details.dart";
-import "package:proxima/viewmodels/dynamic_user_avatar_view_model.dart";
+import "package:proxima/utils/user_avatar_color.dart";
 
 /// A widget that displays the user's avatar.
 /// It provides a [onTap] parameter to handle the user's tap,
 /// which adds an InkWell response.
 /// The [radius] parameter is the radius of the avatar.
-class UserAvatar extends StatelessWidget {
+class UserAvatar extends ConsumerWidget {
   static const initialDisplayNameKey = Key("initialDisplayName");
 
   const UserAvatar({
@@ -25,36 +26,40 @@ class UserAvatar extends StatelessWidget {
   // working and displays the user's profile picture behind the InkWell response.
 
   @override
-  Widget build(BuildContext context) {
-    return CircleAvatar(
-      radius: radius,
-      backgroundColor: DynamicUserAvatarViewModel.centauriToColor(
-        details.userCentauriPoints,
-        Theme.of(context).brightness,
-      ),
-      child: Stack(
-        children: [
-          Center(
-            child: Text(
-              key: initialDisplayNameKey,
-              // Display the first letter of the [displayName] parameter (user's initial).
-              // If the display name is empty, display an empty string (because
-              // it causes an error if it is empty).
-              details.displayName.isEmpty
-                  ? ""
-                  : details.displayName.substring(0, 1),
-            ),
+  Widget build(BuildContext context, WidgetRef ref) {
+    final content = Stack(
+      children: [
+        Center(
+          child: Text(
+            key: initialDisplayNameKey,
+            // Display the first letter of the [displayName] parameter (user's initial).
+            // If the display name is empty, display an empty string (because
+            // it causes an error if it is empty).
+            details.displayName.isEmpty
+                ? ""
+                : details.displayName.substring(0, 1),
           ),
-          Material(
-            shape: const CircleBorder(),
-            clipBehavior: Clip.hardEdge,
-            color: Colors.transparent,
-            child: InkWell(
-              onTap: onTap,
-            ),
+        ),
+        Material(
+          shape: const CircleBorder(),
+          clipBehavior: Clip.hardEdge,
+          color: Colors.transparent,
+          child: InkWell(
+            onTap: onTap,
           ),
-        ],
-      ),
+        ),
+      ],
+    );
+
+    final backgroundColor = centauriToUserAvatarColor(
+      details.centauriPoints,
+      Theme.of(context).brightness,
+    );
+
+    return CircleAvatar(
+      radius: radius,
+      backgroundColor: backgroundColor,
+      child: content,
     );
   }
 }
diff --git a/lib/views/components/content/user_profile_pop_up.dart b/lib/views/components/content/user_profile_pop_up.dart
index eb911d6a..f607b2f8 100644
--- a/lib/views/components/content/user_profile_pop_up.dart
+++ b/lib/views/components/content/user_profile_pop_up.dart
@@ -1,6 +1,6 @@
 import "package:flutter/material.dart";
-import "package:proxima/models/ui/user_avatar_details.dart";
-import "package:proxima/views/components/content/user_avatar/user_avatar.dart";
+import "package:proxima/models/database/user/user_id_firestore.dart";
+import "package:proxima/views/components/content/user_avatar/dynamic_user_avatar.dart";
 import "package:proxima/views/helpers/key_value_list_builder.dart";
 
 /// A pop-up displaying a user's profile, i.e. their display name, username,
@@ -10,12 +10,14 @@ import "package:proxima/views/helpers/key_value_list_builder.dart";
 class UserProfilePopUp extends StatelessWidget {
   final String displayName;
   final String username;
+  final UserIdFirestore userID;
   final int centauriPoints;
 
   const UserProfilePopUp({
     super.key,
     required this.displayName,
     required this.username,
+    required this.userID,
     required this.centauriPoints,
   });
 
@@ -26,16 +28,15 @@ class UserProfilePopUp extends StatelessWidget {
             .addPair("Username", username)
             .addPair("Score", "$centauriPoints Centauri");
 
+    final userAvatar = DynamicUserAvatar(
+      uid: userID,
+      radius: 15,
+    );
+
     return AlertDialog(
       title: Row(
         children: [
-          UserAvatar(
-            details: UserAvatarDetails(
-              displayName: displayName,
-              userCentauriPoints: centauriPoints,
-            ),
-            radius: 15,
-          ),
+          userAvatar,
           const SizedBox(width: 12),
           Text(
             displayName,
diff --git a/lib/views/pages/home/content/feed/components/comment_count.dart b/lib/views/pages/home/content/feed/components/comment_count.dart
index bf5bafcf..e622b6f8 100644
--- a/lib/views/pages/home/content/feed/components/comment_count.dart
+++ b/lib/views/pages/home/content/feed/components/comment_count.dart
@@ -1,17 +1,23 @@
 import "package:flutter/material.dart";
+import "package:hooks_riverpod/hooks_riverpod.dart";
+import "package:proxima/models/database/post/post_id_firestore.dart";
+import "package:proxima/viewmodels/post_comment_count_view_model.dart";
 
 /// This widget is used to display the comment number in the post card.
 /// It contains the comment icon and the number of comments.
-class CommentCount extends StatelessWidget {
-  final int count;
+class CommentCount extends ConsumerWidget {
+  final PostIdFirestore postId;
 
   const CommentCount({
     super.key,
-    required this.count,
+    required this.postId,
   });
 
   @override
-  Widget build(BuildContext context) {
+  Widget build(BuildContext context, WidgetRef ref) {
+    final asyncCount = ref.watch(postCommentCountProvider(postId));
+    final count = asyncCount.value ?? 0;
+
     const icon = Icon(Icons.comment, size: 20);
     final countText = Text(count.toString());
 
diff --git a/lib/views/pages/home/content/feed/components/post_card.dart b/lib/views/pages/home/content/feed/components/post_card.dart
index da25ec41..6efdee77 100644
--- a/lib/views/pages/home/content/feed/components/post_card.dart
+++ b/lib/views/pages/home/content/feed/components/post_card.dart
@@ -79,7 +79,7 @@ class PostCard extends ConsumerWidget {
             onTap: () => _onPostSelect(context, postDetails, ref),
             child: CommentCount(
               key: postCardCommentsNumberKey,
-              count: postDetails.commentNumber,
+              postId: postDetails.postId,
             ),
           ),
         ],
@@ -113,6 +113,7 @@ class PostCard extends ConsumerWidget {
                 key: postCardUserKey,
                 posterUsername: postDetails.ownerUsername,
                 posterDisplayName: postDetails.ownerDisplayName,
+                posterUserID: postDetails.ownerUserID,
                 posterCentauriPoints: postDetails.ownerCentauriPoints,
                 publicationDate: postDetails.publicationDate,
               ),
diff --git a/lib/views/pages/home/content/feed/components/post_card_header.dart b/lib/views/pages/home/content/feed/components/post_card_header.dart
index 6f8ead0b..80f7d4a0 100644
--- a/lib/views/pages/home/content/feed/components/post_card_header.dart
+++ b/lib/views/pages/home/content/feed/components/post_card_header.dart
@@ -1,8 +1,8 @@
 import "package:flutter/material.dart";
 import "package:hooks_riverpod/hooks_riverpod.dart";
-import "package:proxima/models/ui/user_avatar_details.dart";
+import "package:proxima/models/database/user/user_id_firestore.dart";
 import "package:proxima/services/conversion/human_time_service.dart";
-import "package:proxima/views/components/content/user_avatar/user_avatar.dart";
+import "package:proxima/views/components/content/user_avatar/dynamic_user_avatar.dart";
 import "package:proxima/views/components/content/user_profile_pop_up.dart";
 
 /// This widget is used to display the info bar in the post card.
@@ -17,12 +17,14 @@ class PostCardHeader extends ConsumerWidget {
     super.key,
     required this.posterDisplayName,
     required this.posterUsername,
+    required this.posterUserID,
     required this.posterCentauriPoints,
     required this.publicationDate,
   });
 
   final String posterDisplayName;
   final String posterUsername;
+  final UserIdFirestore posterUserID;
   final int posterCentauriPoints;
   final DateTime publicationDate;
 
@@ -32,6 +34,7 @@ class PostCardHeader extends ConsumerWidget {
       builder: (BuildContext context) => UserProfilePopUp(
         displayName: posterDisplayName,
         username: posterUsername,
+        userID: posterUserID,
         centauriPoints: posterCentauriPoints,
       ),
     );
@@ -78,11 +81,8 @@ class PostCardHeader extends ConsumerWidget {
     return Row(
       mainAxisAlignment: MainAxisAlignment.start,
       children: [
-        UserAvatar(
-          details: UserAvatarDetails(
-            displayName: posterDisplayName,
-            userCentauriPoints: posterCentauriPoints,
-          ),
+        DynamicUserAvatar(
+          uid: posterUserID,
           radius: 12,
           onTap: () => onTap(context),
           key: avatarKey,
diff --git a/lib/views/pages/home/content/ranking/components/ranking_card.dart b/lib/views/pages/home/content/ranking/components/ranking_card.dart
index da83338b..c227de5d 100644
--- a/lib/views/pages/home/content/ranking/components/ranking_card.dart
+++ b/lib/views/pages/home/content/ranking/components/ranking_card.dart
@@ -1,7 +1,6 @@
 import "package:flutter/material.dart";
 import "package:proxima/models/ui/ranking/ranking_element_details.dart";
-import "package:proxima/models/ui/user_avatar_details.dart";
-import "package:proxima/views/components/content/user_avatar/user_avatar.dart";
+import "package:proxima/views/components/content/user_avatar/dynamic_user_avatar.dart";
 import "package:proxima/views/components/content/user_profile_pop_up.dart";
 
 /// A widget that displays a ranking card.
@@ -65,6 +64,7 @@ class RankingCard extends StatelessWidget {
             builder: (BuildContext context) => UserProfilePopUp(
               displayName: rankingElementDetails.userDisplayName,
               username: rankingElementDetails.userUserName,
+              userID: rankingElementDetails.userID,
               centauriPoints: rankingElementDetails.centauriPoints,
             ),
           ),
@@ -96,17 +96,13 @@ class RankingCard extends StatelessWidget {
       ),
     );
 
-    final userDetails = UserAvatarDetails(
-      displayName: rankingElementDetails.userDisplayName,
-      userCentauriPoints: rankingElementDetails.centauriPoints,
-    );
     final userInfo = Padding(
       padding: const EdgeInsets.all(8),
       child: Row(
         children: [
-          UserAvatar(
+          DynamicUserAvatar(
             key: userRankAvatarKey,
-            details: userDetails,
+            uid: rankingElementDetails.userID,
             radius: 22,
           ),
           Flexible(child: userDisplayNameText),
diff --git a/lib/views/pages/post/components/comment/comment_post_widget.dart b/lib/views/pages/post/components/comment/comment_post_widget.dart
index 0a061a65..c5f0d630 100644
--- a/lib/views/pages/post/components/comment/comment_post_widget.dart
+++ b/lib/views/pages/post/components/comment/comment_post_widget.dart
@@ -24,6 +24,7 @@ class CommentPostWidget extends StatelessWidget {
           key: commentUserWidgetKey,
           posterDisplayName: commentPost.ownerDisplayName,
           posterUsername: commentPost.ownerUsername,
+          posterUserID: commentPost.ownerUserID,
           posterCentauriPoints: commentPost.ownerCentauriPoints,
           publicationDate: commentPost.publicationDate,
         ),
diff --git a/lib/views/pages/post/components/complete_post.dart b/lib/views/pages/post/components/complete_post.dart
index c53ad584..93c08082 100644
--- a/lib/views/pages/post/components/complete_post.dart
+++ b/lib/views/pages/post/components/complete_post.dart
@@ -46,6 +46,7 @@ class CompletePost extends StatelessWidget {
             key: postUserBarKey,
             posterDisplayName: post.ownerDisplayName,
             posterUsername: post.ownerUsername,
+            posterUserID: post.ownerUserID,
             posterCentauriPoints: post.ownerCentauriPoints,
             publicationDate: post.publicationDate,
           ),
diff --git a/lib/views/pages/profile/components/profile_app_bar.dart b/lib/views/pages/profile/components/profile_app_bar.dart
index 9cea519e..3c2a76bf 100644
--- a/lib/views/pages/profile/components/profile_app_bar.dart
+++ b/lib/views/pages/profile/components/profile_app_bar.dart
@@ -1,20 +1,20 @@
 import "package:flutter/material.dart";
-import "package:proxima/models/database/user/user_data.dart";
+import "package:proxima/models/database/user/user_firestore.dart";
 import "package:proxima/views/navigation/leading_back_button/leading_back_button.dart";
 import "package:proxima/views/pages/profile/components/logout_button.dart";
 import "package:proxima/views/pages/profile/components/user_account.dart";
 
+// This widget displays the profile of a user as an app bar.
 class ProfileAppBar extends AppBar {
-  final UserData userData;
+  // The user to display
+  final UserFirestore user;
 
   ProfileAppBar({
     super.key,
-    required this.userData,
+    required this.user,
   }) : super(
           leading: const LeadingBackButton(),
-          title: UserAccount(
-            userData: userData,
-          ),
+          title: UserAccount(user: user),
           actions: [
             const LogoutButton(),
           ],
diff --git a/lib/views/pages/profile/components/user_account.dart b/lib/views/pages/profile/components/user_account.dart
index 6558e96b..5ecab36a 100644
--- a/lib/views/pages/profile/components/user_account.dart
+++ b/lib/views/pages/profile/components/user_account.dart
@@ -1,7 +1,6 @@
 import "package:flutter/material.dart";
-import "package:proxima/models/database/user/user_data.dart";
-import "package:proxima/models/ui/user_avatar_details.dart";
-import "package:proxima/views/components/content/user_avatar/user_avatar.dart";
+import "package:proxima/models/database/user/user_firestore.dart";
+import "package:proxima/views/components/content/user_avatar/dynamic_user_avatar.dart";
 
 /// This widget display the user info in the profile page
 class UserAccount extends StatelessWidget {
@@ -10,15 +9,18 @@ class UserAccount extends StatelessWidget {
 
   const UserAccount({
     super.key,
-    required this.userData,
+    required this.user,
   });
 
-  final UserData userData;
+  // The user to display
+  final UserFirestore user;
 
   @override
   Widget build(BuildContext context) {
     final textStyle = Theme.of(context).textTheme.titleSmall;
 
+    final userData = user.data;
+
     final displayName = Text(
       userData.displayName,
       style: textStyle,
@@ -31,8 +33,8 @@ class UserAccount extends StatelessWidget {
       "${userData.username} · ${userData.centauriPoints} Centauri",
     );
 
-    final profilePicture = UserAvatar(
-      details: UserAvatarDetails.fromUserData(userData),
+    final profilePicture = DynamicUserAvatar(
+      uid: user.uid,
       radius: 20,
     );
 
diff --git a/lib/views/pages/profile/profile_page.dart b/lib/views/pages/profile/profile_page.dart
index 3678da50..e5933e2a 100644
--- a/lib/views/pages/profile/profile_page.dart
+++ b/lib/views/pages/profile/profile_page.dart
@@ -44,10 +44,11 @@ class ProfilePage extends ConsumerWidget {
     return CircularValue(
       future: asyncUserData,
       builder: (context, value) {
+        final user = value.firestoreUser;
         return DefaultTabController(
           length: 2,
           child: Scaffold(
-            appBar: ProfileAppBar(userData: value.firestoreUser.data),
+            appBar: ProfileAppBar(user: user),
             body: Container(
               padding: const EdgeInsets.only(left: 8, right: 8, bottom: 8),
               child: const Column(
diff --git a/test/end2end/app_actions.dart b/test/end2end/app_actions.dart
index 154b45c9..92038ef3 100644
--- a/test/end2end/app_actions.dart
+++ b/test/end2end/app_actions.dart
@@ -322,11 +322,21 @@ class AppActions {
     await tester.pumpAndSettle();
 
     // Check that the post content is displayed
-    expect(find.text(comment), findsOneWidget);
+    final commentText = find.text(comment);
+    expect(commentText, findsOneWidget);
 
-    // Find the delete button on card
-    final deleteButton = find.byKey(ProfileInfoCard.deleteButtonCardKey);
-    expect(deleteButton, findsOneWidget);
+    // Find and tap the delete button on the card
+    final commentCard = find.ancestor(
+      of: commentText,
+      matching: find.byKey(ProfileInfoCard.infoCardKey),
+    );
+    expect(commentCard, findsOne);
+
+    final deleteButton = find.descendant(
+      of: commentCard,
+      matching: find.byKey(ProfileInfoCard.deleteButtonCardKey),
+    );
+    expect(deleteButton, findsOne);
 
     await tester.tap(deleteButton);
     await tester.pumpAndSettle(delayNeededForAsyncFunctionExecution);
diff --git a/test/end2end/app_test.dart b/test/end2end/app_test.dart
index 3a6175fc..ed3ea66f 100644
--- a/test/end2end/app_test.dart
+++ b/test/end2end/app_test.dart
@@ -11,7 +11,6 @@ import "package:proxima/services/database/firestore_service.dart";
 import "package:proxima/services/sensors/geolocation_service.dart";
 import "package:proxima/views/navigation/bottom_navigation_bar/navigation_bar_routes.dart";
 import "package:proxima/views/pages/home/content/challenge/challenge_list.dart";
-import "package:proxima/views/pages/home/content/feed/post_feed.dart";
 import "package:proxima/views/pages/profile/components/profile_app_bar.dart";
 import "package:proxima/views/proxima_app.dart";
 
@@ -164,17 +163,19 @@ void main() {
     await AppActions.loginToCreateAccount(tester);
     await AppActions.createAccountToHome(tester);
     await AppActions.createPost(tester, testPostTitle, testPostDescription);
-    await AppActions.openPost(tester, testPostTitle);
-    const comment = "I like turtles too!";
-    await AppActions.addComment(tester, comment);
-
-    // back to feed
-    await AppActions.navigateBack(tester);
-    await AppActions.flingRefresh(tester, find.byType(PostFeed));
+    await AppActions.expectCommentCount(tester, testPostTitle, 0);
+
+    // Add two comments
+    const comments = ["I like turtles too!", "I prefer elephants"];
+    for (final (i, comment) in comments.indexed) {
+      await AppActions.openPost(tester, testPostTitle);
+      await AppActions.addComment(tester, comment);
+      await AppActions.navigateBack(tester);
+      await AppActions.expectCommentCount(tester, testPostTitle, i + 1);
+    }
 
-    // expect comment count to be correct
-    AppActions.expectCommentCount(tester, testPostTitle, 1);
-    await AppActions.deleteComment(tester, comment);
-    AppActions.expectCommentCount(tester, testPostTitle, 0);
+    // Deleting a comment should reduce the comment count
+    await AppActions.deleteComment(tester, comments.first);
+    await AppActions.expectCommentCount(tester, testPostTitle, 1);
   });
 }
diff --git a/test/mocks/data/post_comment.dart b/test/mocks/data/post_comment.dart
index cd32a8a0..6e08d192 100644
--- a/test/mocks/data/post_comment.dart
+++ b/test/mocks/data/post_comment.dart
@@ -1,3 +1,4 @@
+import "package:proxima/models/database/user/user_id_firestore.dart";
 import "package:proxima/models/ui/comment_details.dart";
 
 import "datetime.dart";
@@ -8,6 +9,7 @@ final List<CommentDetails> testComments = [
         "I totally agree! It's the little things in life that make all the difference.",
     ownerDisplayName: "SunnySkyWalker",
     ownerUsername: "SunnySkyWalkerUsername",
+    ownerUserID: const UserIdFirestore(value: "SunnySkyWalkerID"),
     ownerCentauriPoints: 12,
     publicationDate: publicationDate1,
   ),
@@ -16,6 +18,7 @@ final List<CommentDetails> testComments = [
         "Just what I needed to read today. Sometimes, simplicity is key to happiness.",
     ownerDisplayName: "BookishBee",
     ownerUsername: "BookishBeeUsername",
+    ownerUserID: const UserIdFirestore(value: "BookishBeeID"),
     ownerCentauriPoints: 123,
     publicationDate: publicationDate1,
   ),
@@ -24,6 +27,7 @@ final List<CommentDetails> testComments = [
         "Love this reminder! I try to start each day with a grateful heart.",
     ownerDisplayName: "MilesOfSmiles",
     ownerUsername: "MilesOfSmilesUsername",
+    ownerUserID: const UserIdFirestore(value: "MilesOfSmilesID"),
     ownerCentauriPoints: 12333,
     publicationDate: publicationDate1,
   ),
@@ -32,6 +36,7 @@ final List<CommentDetails> testComments = [
         "Couldn't agree more! Walking my dog and enjoying nature always lifts my mood.",
     ownerDisplayName: "SimpleJoys247",
     ownerUsername: "SimpleJoys247Username",
+    ownerUserID: const UserIdFirestore(value: "SimpleJoys247ID"),
     ownerCentauriPoints: 1729,
     publicationDate: publicationDate1,
   ),
@@ -40,6 +45,7 @@ final List<CommentDetails> testComments = [
         "This is so true. Just being outdoors makes me feel at peace and genuinely happy.",
     ownerDisplayName: "HappyHiker42",
     ownerUsername: "HappyHiker42Username",
+    ownerUserID: const UserIdFirestore(value: "HappyHiker42ID"),
     ownerCentauriPoints: 31415,
     publicationDate: publicationDate1,
   ),
@@ -50,6 +56,7 @@ final List<CommentDetails> unequalComments = [
     content: "content1",
     ownerDisplayName: "username1",
     ownerUsername: "username1username",
+    ownerUserID: const UserIdFirestore(value: "username1ID"),
     ownerCentauriPoints: 2,
     publicationDate: publicationDate1,
   ),
@@ -58,6 +65,7 @@ final List<CommentDetails> unequalComments = [
     content: "content2",
     ownerDisplayName: "username1",
     ownerUsername: "username1username",
+    ownerUserID: const UserIdFirestore(value: "username1ID"),
     ownerCentauriPoints: 0,
     publicationDate: publicationDate1,
   ),
@@ -65,7 +73,8 @@ final List<CommentDetails> unequalComments = [
   CommentDetails(
     content: "content1",
     ownerDisplayName: "username2",
-    ownerUsername: "username2username",
+    ownerUsername: "username1username",
+    ownerUserID: const UserIdFirestore(value: "username1ID"),
     ownerCentauriPoints: 2,
     publicationDate: publicationDate1,
   ),
@@ -75,7 +84,18 @@ final List<CommentDetails> unequalComments = [
     content: "content1",
     ownerDisplayName: "username1",
     ownerUsername: "username1username",
+    ownerUserID: const UserIdFirestore(value: "username1ID"),
     ownerCentauriPoints: 2,
     publicationDate: publicationDate1.add(const Duration(days: 1)),
   ),
+
+  // Different ownerUserID
+  CommentDetails(
+    content: "content1",
+    ownerDisplayName: "username1",
+    ownerUsername: "username1username",
+    ownerUserID: const UserIdFirestore(value: "username2ID"),
+    ownerCentauriPoints: 2,
+    publicationDate: publicationDate1,
+  ),
 ];
diff --git a/test/mocks/data/post_overview.dart b/test/mocks/data/post_overview.dart
index 65bcb0bd..75d0202b 100644
--- a/test/mocks/data/post_overview.dart
+++ b/test/mocks/data/post_overview.dart
@@ -1,4 +1,5 @@
 import "package:proxima/models/database/post/post_id_firestore.dart";
+import "package:proxima/models/database/user/user_id_firestore.dart";
 import "package:proxima/models/ui/post_details.dart";
 
 import "datetime.dart";
@@ -14,6 +15,7 @@ final List<PostDetails> testPosts = [
     // to simplify testing
     ownerDisplayName: "Proxima",
     ownerUsername: "Elephant",
+    ownerUserID: const UserIdFirestore(value: "ProximaUserID"),
     ownerCentauriPoints: 32,
     publicationDate: publicationDate1,
     distance: 20,
@@ -27,6 +29,7 @@ final List<PostDetails> testPosts = [
     commentNumber: 5,
     ownerDisplayName: "Proxima",
     ownerUsername: "ProximaUsername",
+    ownerUserID: const UserIdFirestore(value: "ProximaUserID"),
     ownerCentauriPoints: 7,
     publicationDate: publicationDate1,
     distance: 20,
@@ -40,6 +43,7 @@ final List<PostDetails> testPosts = [
     commentNumber: 829,
     ownerDisplayName: "Proxima",
     ownerUsername: "ProximaUsername",
+    ownerUserID: const UserIdFirestore(value: "ProximaUserID"),
     ownerCentauriPoints: 218281828,
     publicationDate: publicationDate1,
     distance: 20,
@@ -55,6 +59,7 @@ final timeDistancePost = PostDetails(
   commentNumber: 5,
   ownerDisplayName: "owner",
   ownerUsername: "ownerUsername",
+  ownerUserID: const UserIdFirestore(value: "ownerID"),
   ownerCentauriPoints: 911,
   publicationDate: DateTime.utc(1999),
   distance: 100,
diff --git a/test/mocks/data/ranking_data.dart b/test/mocks/data/ranking_data.dart
index 93bdef21..d2eaaeb8 100644
--- a/test/mocks/data/ranking_data.dart
+++ b/test/mocks/data/ranking_data.dart
@@ -1,4 +1,5 @@
 import "package:collection/collection.dart";
+import "package:proxima/models/database/user/user_id_firestore.dart";
 import "package:proxima/models/ui/ranking/ranking_details.dart";
 import "package:proxima/models/ui/ranking/ranking_element_details.dart";
 
@@ -23,6 +24,7 @@ final List<RankingElementDetails> mockRankingElementDetailsList =
           (index, user) => RankingElementDetails(
             userDisplayName: user.keys.first,
             userUserName: "u_${user.keys.first}",
+            userID: UserIdFirestore(value: "uid_${user.keys.first}"),
             centauriPoints: user.values.first,
             userRank: index + 1,
           ),
@@ -41,6 +43,7 @@ final RankingElementDetails testUserRankingElementDetails =
     RankingElementDetails(
   userDisplayName: testingUserData.displayName,
   userUserName: testingUserData.username,
+  userID: testingUserFirestoreId,
   centauriPoints: 0,
   userRank: 9,
 );
diff --git a/test/mocks/overrides/override_dynamic_user_avatar_view_model.dart b/test/mocks/overrides/override_dynamic_user_avatar_view_model.dart
index c737137f..f34f030c 100644
--- a/test/mocks/overrides/override_dynamic_user_avatar_view_model.dart
+++ b/test/mocks/overrides/override_dynamic_user_avatar_view_model.dart
@@ -1,27 +1,33 @@
 import "package:hooks_riverpod/hooks_riverpod.dart";
 import "package:proxima/models/database/user/user_id_firestore.dart";
 import "package:proxima/models/ui/user_avatar_details.dart";
-import "package:proxima/services/database/challenge_repository_service.dart";
 import "package:proxima/viewmodels/dynamic_user_avatar_view_model.dart";
 
 import "../data/firebase_auth_user.dart";
+import "../data/firestore_user.dart";
 
 /// A mock implementation of the [DynamicUserAvatarViewModel] class.
 class MockDynamicUserAvatarViewModel
     extends AutoDisposeFamilyAsyncNotifier<UserAvatarDetails, UserIdFirestore?>
     implements DynamicUserAvatarViewModel {
   final Future<UserAvatarDetails> Function(UserIdFirestore? arg) _build;
+  final Future<void> Function() _onRefresh;
 
   MockDynamicUserAvatarViewModel({
     Future<UserAvatarDetails> Function(UserIdFirestore? arg)? build,
-  }) : _build = build ??
+    Future<void> Function()? onRefresh,
+  })  : _build = build ??
             ((_) async => const UserAvatarDetails(
                   displayName: "",
-                  userCentauriPoints: null,
-                ));
+                  centauriPoints: null,
+                )),
+        _onRefresh = onRefresh ?? (() async {});
 
   @override
   Future<UserAvatarDetails> build(UserIdFirestore? arg) => _build(arg);
+
+  @override
+  Future<void> refresh() => _onRefresh();
 }
 
 final mockDynamicUserAvatarViewModelTestLoginUserOverride = [
@@ -29,7 +35,7 @@ final mockDynamicUserAvatarViewModelTestLoginUserOverride = [
     () => MockDynamicUserAvatarViewModel(
       build: (userUID) async => UserAvatarDetails(
         displayName: testingLoginUser.displayName!,
-        userCentauriPoints: ChallengeRepositoryService.soloChallengeReward * 50,
+        centauriPoints: testingUserData.centauriPoints,
       ),
     ),
   ),
@@ -40,7 +46,7 @@ final mockDynamicUserAvatarViewModelEmptyDisplayNameOverride = [
     () => MockDynamicUserAvatarViewModel(
       build: (userUID) async => const UserAvatarDetails(
         displayName: "",
-        userCentauriPoints: null,
+        centauriPoints: null,
       ),
     ),
   ),
diff --git a/test/mocks/overrides/override_post_comment_count_view_model.dart b/test/mocks/overrides/override_post_comment_count_view_model.dart
new file mode 100644
index 00000000..7782a9fe
--- /dev/null
+++ b/test/mocks/overrides/override_post_comment_count_view_model.dart
@@ -0,0 +1,30 @@
+import "package:hooks_riverpod/hooks_riverpod.dart";
+import "package:proxima/models/database/post/post_id_firestore.dart";
+import "package:proxima/viewmodels/post_comment_count_view_model.dart";
+
+/// A mock implementation of the [PostCommentCountViewModel] class.
+/// Its state is always the same and can be set in the constructor.
+class MockPostCommentCountViewModel
+    extends FamilyAsyncNotifier<int, PostIdFirestore>
+    implements PostCommentCountViewModel {
+  final int count;
+
+  /// Creates a new [MockPostCommentCountViewModel] with the given [count],
+  /// which is the value that will always be returned by this view-model.
+  MockPostCommentCountViewModel({this.count = 0});
+
+  @override
+  Future<int> build(PostIdFirestore arg) async {
+    return count;
+  }
+
+  @override
+  Future<void> refresh() async {
+    state = const AsyncValue.loading();
+    state = await AsyncValue.guard(() => build(arg));
+  }
+}
+
+final zeroPostCommentCountOverride = [
+  postCommentCountProvider.overrideWith(() => MockPostCommentCountViewModel()),
+];
diff --git a/test/mocks/overrides/override_posts_feed_view_model.dart b/test/mocks/overrides/override_posts_feed_view_model.dart
index bf426fda..7e0c4123 100644
--- a/test/mocks/overrides/override_posts_feed_view_model.dart
+++ b/test/mocks/overrides/override_posts_feed_view_model.dart
@@ -4,6 +4,7 @@ import "package:proxima/models/ui/post_details.dart";
 import "package:proxima/viewmodels/posts_feed_view_model.dart";
 
 import "../data/post_overview.dart";
+import "override_post_comment_count_view_model.dart";
 
 /// A mock implementation of the [PostsFeedViewModel] class.
 /// This class is particularly useful for the UI tests where we want to expose
@@ -35,6 +36,8 @@ final mockNonEmptyHomeViewModelOverride = [
   postsFeedViewModelProvider.overrideWith(
     () => MockPostsFeedViewModel(build: () async => testPosts),
   ),
+  // The posts don't exist in the database, so we also override their comment count to 0
+  ...zeroPostCommentCountOverride,
 ];
 
 final mockLoadingHomeViewModelOverride = [
diff --git a/test/mocks/providers/provider_ranking.dart b/test/mocks/providers/provider_ranking.dart
index 076f2c8c..18335e7b 100644
--- a/test/mocks/providers/provider_ranking.dart
+++ b/test/mocks/providers/provider_ranking.dart
@@ -1,4 +1,5 @@
 import "package:fake_cloud_firestore/fake_cloud_firestore.dart";
+import "package:firebase_core/firebase_core.dart";
 import "package:flutter/material.dart";
 import "package:hooks_riverpod/hooks_riverpod.dart";
 import "package:proxima/services/database/firestore_service.dart";
@@ -6,6 +7,8 @@ import "package:proxima/viewmodels/login_view_model.dart";
 import "package:proxima/views/pages/home/content/ranking/ranking_page.dart";
 
 import "../data/firestore_user.dart";
+import "../overrides/override_dynamic_user_avatar_view_model.dart";
+import "../services/setup_firebase_mocks.dart";
 
 /// Returns a testing [ProviderContainer] which purpose is to test the ranking
 /// view model.
@@ -13,10 +16,13 @@ import "../data/firestore_user.dart";
 Future<ProviderContainer> rankingProviderContainerWithTestingUser(
   FakeFirebaseFirestore fakeFirebaseFirestore,
 ) async {
+  setupFirebaseAuthMocks();
+  await Firebase.initializeApp();
   await setUserFirestore(fakeFirebaseFirestore, testingUserFirestore);
 
   return ProviderContainer(
     overrides: [
+      ...mockDynamicUserAvatarViewModelTestLoginUserOverride,
       firestoreProvider.overrideWithValue(fakeFirebaseFirestore),
       validLoggedInUserIdProvider.overrideWithValue(testingUserFirestoreId),
     ],
@@ -25,16 +31,16 @@ Future<ProviderContainer> rankingProviderContainerWithTestingUser(
 
 /// Returns a testable [RankingPage] already overriden by providers
 /// of [rankingProviderContainerWithTestingUser].
-Future<MaterialApp> rankingPageMockApp(
+Future<UncontrolledProviderScope> rankingPageMockApp(
   FakeFirebaseFirestore fakeFirebaseFirestore,
 ) async {
   final rankingContainer =
       await rankingProviderContainerWithTestingUser(fakeFirebaseFirestore);
 
-  return MaterialApp(
-    home: UncontrolledProviderScope(
-      container: rankingContainer,
-      child: const RankingPage(),
+  return UncontrolledProviderScope(
+    container: rankingContainer,
+    child: const MaterialApp(
+      home: RankingPage(),
     ),
   );
 }
diff --git a/test/models/ui/comment_details_test.dart b/test/models/ui/comment_details_test.dart
index ab4bdb6b..eed9e0fe 100644
--- a/test/models/ui/comment_details_test.dart
+++ b/test/models/ui/comment_details_test.dart
@@ -11,6 +11,7 @@ void main() {
         commentPost.content,
         commentPost.ownerDisplayName,
         commentPost.ownerUsername,
+        commentPost.ownerUserID,
         commentPost.ownerCentauriPoints,
         commentPost.publicationDate,
       );
@@ -31,21 +32,28 @@ void main() {
       final commentPost = unequalComments[0];
       final commentPostOther = unequalComments[1];
 
-      expect(commentPost != commentPostOther, true);
+      expect(commentPost, isNot(equals(commentPostOther)));
     });
 
     test("inequality test on username", () {
       final commentPost = unequalComments[0];
       final commentPostOther = unequalComments[2];
 
-      expect(commentPost != commentPostOther, true);
+      expect(commentPost, isNot(equals(commentPostOther)));
     });
 
     test("inequality test on publication time", () {
       final commentPost = unequalComments[0];
       final commentPostOther = unequalComments[3];
 
-      expect(commentPost != commentPostOther, true);
+      expect(commentPost, isNot(equals(commentPostOther)));
+    });
+
+    test("inequality test on owner ID", () {
+      final commentPost = unequalComments[0];
+      final commentPostOther = unequalComments[4];
+
+      expect(commentPost, isNot(equals(commentPostOther)));
     });
   });
 }
diff --git a/test/models/ui/post_details_test.dart b/test/models/ui/post_details_test.dart
index 4da7267c..7df2a570 100644
--- a/test/models/ui/post_details_test.dart
+++ b/test/models/ui/post_details_test.dart
@@ -15,6 +15,7 @@ void main() {
         postDetails.commentNumber,
         postDetails.ownerDisplayName,
         postDetails.ownerUsername,
+        postDetails.ownerUserID,
         postDetails.ownerCentauriPoints,
         postDetails.publicationDate,
         postDetails.distance,
diff --git a/test/models/ui/ranking/ranking_details_test.dart b/test/models/ui/ranking/ranking_details_test.dart
index 847fa82d..3dd12570 100644
--- a/test/models/ui/ranking/ranking_details_test.dart
+++ b/test/models/ui/ranking/ranking_details_test.dart
@@ -10,23 +10,26 @@ void main() {
     late List<RankingElementDetails> listRankingElementDetails;
 
     setUp(() {
-      final usersList = FirestoreUserGenerator.generateUserData(5);
-      listRankingElementDetails = usersList
-          .mapIndexed(
-            (index, user) => RankingElementDetails(
-              userDisplayName: user.displayName,
-              userUserName: user.username,
-              centauriPoints: user.centauriPoints,
-              userRank: index + 1,
-            ),
-          )
-          .toList();
+      final usersList = FirestoreUserGenerator.generateUserFirestore(5);
+      listRankingElementDetails = usersList.mapIndexed(
+        (index, user) {
+          final userData = user.data;
+          return RankingElementDetails(
+            userDisplayName: userData.displayName,
+            userUserName: userData.username,
+            userID: user.uid,
+            centauriPoints: userData.centauriPoints,
+            userRank: index + 1,
+          );
+        },
+      ).toList();
     });
 
     test("hash", () {
       final userRankingElementDetail = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 10,
         userRank: 6,
       );
@@ -50,6 +53,7 @@ void main() {
       final userRankingElementDetail = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 10,
         userRank: 6,
       );
@@ -71,6 +75,7 @@ void main() {
       final userRankingElementDetail1 = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 10,
         userRank: 6,
       );
@@ -83,6 +88,7 @@ void main() {
       final userRankingElementDetail2 = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 12,
         userRank: 7,
       );
@@ -99,6 +105,7 @@ void main() {
       final userRankingElementDetail = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 10,
         userRank: 6,
       );
@@ -108,17 +115,19 @@ void main() {
         rankElementDetailsList: listRankingElementDetails,
       );
 
-      final userList2 = FirestoreUserGenerator.generateUserData(3);
-      final listRankingElementDetails2 = userList2
-          .mapIndexed(
-            (index, user) => RankingElementDetails(
-              userDisplayName: user.displayName,
-              userUserName: user.username,
-              centauriPoints: user.centauriPoints,
-              userRank: index + 1,
-            ),
-          )
-          .toList();
+      final userList2 = FirestoreUserGenerator.generateUserFirestore(3);
+      final listRankingElementDetails2 = userList2.mapIndexed(
+        (index, user) {
+          final userData = user.data;
+          return RankingElementDetails(
+            userDisplayName: userData.displayName,
+            userUserName: userData.username,
+            userID: user.uid,
+            centauriPoints: userData.centauriPoints,
+            userRank: index + 1,
+          );
+        },
+      ).toList();
 
       final rankingDetails2 = RankingDetails(
         userRankElementDetails: userRankingElementDetail,
@@ -135,21 +144,24 @@ void main() {
     final userRankingElementDetail = RankingElementDetails(
       userDisplayName: testingUserData.displayName,
       userUserName: testingUserData.username,
+      userID: testingUserFirestoreId,
       centauriPoints: 10,
       userRank: 6,
     );
 
-    final usersList = FirestoreUserGenerator.generateUserData(5);
-    final listRankingElementDetails = usersList
-        .mapIndexed(
-          (index, user) => RankingElementDetails(
-            userDisplayName: user.displayName,
-            userUserName: user.username,
-            centauriPoints: user.centauriPoints,
-            userRank: index == 1 ? null : index + 1,
-          ),
-        )
-        .toList();
+    final usersList = FirestoreUserGenerator.generateUserFirestore(5);
+    final listRankingElementDetails = usersList.mapIndexed(
+      (index, user) {
+        final userData = user.data;
+        return RankingElementDetails(
+          userDisplayName: userData.displayName,
+          userUserName: userData.username,
+          userID: user.uid,
+          centauriPoints: userData.centauriPoints,
+          userRank: index == 1 ? null : index + 1,
+        );
+      },
+    ).toList();
 
     expect(
       () => {
diff --git a/test/models/ui/ranking/ranking_element_details_test.dart b/test/models/ui/ranking/ranking_element_details_test.dart
index 797c824f..e1e1c6a1 100644
--- a/test/models/ui/ranking/ranking_element_details_test.dart
+++ b/test/models/ui/ranking/ranking_element_details_test.dart
@@ -1,4 +1,5 @@
 import "package:flutter_test/flutter_test.dart";
+import "package:proxima/models/database/user/user_id_firestore.dart";
 import "package:proxima/models/ui/ranking/ranking_element_details.dart";
 
 import "../../../mocks/data/firestore_user.dart";
@@ -9,6 +10,7 @@ void main() {
       final rankingElementDetail = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 10,
         userRank: 1,
       );
@@ -16,6 +18,7 @@ void main() {
       final expectedHash = Object.hash(
         rankingElementDetail.userDisplayName,
         rankingElementDetail.userUserName,
+        rankingElementDetail.userID,
         rankingElementDetail.centauriPoints,
         rankingElementDetail.userRank,
       );
@@ -29,6 +32,7 @@ void main() {
       final rankingElementDetail1 = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 10,
         userRank: 1,
       );
@@ -36,17 +40,19 @@ void main() {
       final rankingElementDetail2 = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 10,
         userRank: 1,
       );
 
-      expect(rankingElementDetail1 == rankingElementDetail2, isTrue);
+      expect(rankingElementDetail1, rankingElementDetail2);
     });
 
     test("!= userDisplayName", () {
       final rankingElementDetail1 = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 10,
         userRank: 1,
       );
@@ -54,17 +60,19 @@ void main() {
       final rankingElementDetail2 = RankingElementDetails(
         userDisplayName: "${testingUserData.displayName}_2",
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 10,
         userRank: 1,
       );
 
-      expect(rankingElementDetail1 == rankingElementDetail2, isFalse);
+      expect(rankingElementDetail1, isNot(equals(rankingElementDetail2)));
     });
 
     test("!= centauriPoints", () {
       final rankingElementDetail1 = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 10,
         userRank: 1,
       );
@@ -72,17 +80,19 @@ void main() {
       final rankingElementDetail2 = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 12,
         userRank: 1,
       );
 
-      expect(rankingElementDetail1 == rankingElementDetail2, isFalse);
+      expect(rankingElementDetail1, isNot(equals(rankingElementDetail2)));
     });
 
     test("!= userRank", () {
       final rankingElementDetail1 = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 10,
         userRank: 1,
       );
@@ -90,11 +100,32 @@ void main() {
       final rankingElementDetail2 = RankingElementDetails(
         userDisplayName: testingUserData.displayName,
         userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
         centauriPoints: 10,
         userRank: 2,
       );
 
-      expect(rankingElementDetail1 == rankingElementDetail2, isFalse);
+      expect(rankingElementDetail1, isNot(equals(rankingElementDetail2)));
+    });
+
+    test("!= userID", () {
+      final rankingElementDetail1 = RankingElementDetails(
+        userDisplayName: testingUserData.displayName,
+        userUserName: testingUserData.username,
+        userID: testingUserFirestoreId,
+        centauriPoints: 10,
+        userRank: 1,
+      );
+
+      final rankingElementDetail2 = RankingElementDetails(
+        userDisplayName: testingUserData.displayName,
+        userUserName: testingUserData.username,
+        userID: const UserIdFirestore(value: "not_the_same_uid"),
+        centauriPoints: 10,
+        userRank: 1,
+      );
+
+      expect(rankingElementDetail1, isNot(equals(rankingElementDetail2)));
     });
   });
 }
diff --git a/test/models/ui/user_avatar_details_test.dart b/test/models/ui/user_avatar_details_test.dart
index 96a49f1f..9adb8f5a 100644
--- a/test/models/ui/user_avatar_details_test.dart
+++ b/test/models/ui/user_avatar_details_test.dart
@@ -8,13 +8,13 @@ void main() {
     late UserAvatarDetails userAvatarDetails;
 
     setUp(() {
-      userAvatarDetails = UserAvatarDetails.fromUserData(testingUserData);
+      userAvatarDetails = UserAvatarDetails.fromUser(testingUserFirestore);
     });
 
     test("Hash overrides correctly", () {
       final expectedHash = Object.hash(
         userAvatarDetails.displayName,
-        userAvatarDetails.userCentauriPoints,
+        userAvatarDetails.centauriPoints,
       );
 
       final actualHash = userAvatarDetails.hashCode;
@@ -25,7 +25,7 @@ void main() {
       // Copy made by the other constructor on purpose
       final userAvatarDetailsCopy = UserAvatarDetails(
         displayName: testingUserData.displayName,
-        userCentauriPoints: testingUserData.centauriPoints,
+        centauriPoints: testingUserData.centauriPoints,
       );
 
       expect(userAvatarDetails, equals(userAvatarDetailsCopy));
diff --git a/test/viewmodels/dynamic_user_avatar_view_model_integration_test.dart b/test/viewmodels/dynamic_user_avatar_view_model_integration_test.dart
new file mode 100644
index 00000000..d84e0434
--- /dev/null
+++ b/test/viewmodels/dynamic_user_avatar_view_model_integration_test.dart
@@ -0,0 +1,82 @@
+import "package:fake_cloud_firestore/fake_cloud_firestore.dart";
+import "package:flutter_test/flutter_test.dart";
+import "package:hooks_riverpod/hooks_riverpod.dart";
+import "package:proxima/services/database/challenge_repository_service.dart";
+import "package:proxima/services/database/firestore_service.dart";
+import "package:proxima/viewmodels/challenge_view_model.dart";
+import "package:proxima/viewmodels/dynamic_user_avatar_view_model.dart";
+import "package:proxima/viewmodels/login_view_model.dart";
+
+import "../mocks/data/firestore_challenge.dart";
+import "../mocks/data/firestore_post.dart";
+import "../mocks/data/firestore_user.dart";
+import "../mocks/data/geopoint.dart";
+import "../utils/delay_async_func.dart";
+
+void main() {
+  late FakeFirebaseFirestore fakeFireStore;
+  late ProviderContainer container;
+
+  setUp(() {
+    fakeFireStore = FakeFirebaseFirestore();
+  });
+
+  group(
+      "Dynamic User Avatar check Centauri points ViewModel part integration testing using challenges",
+      () {
+    late FirestoreChallengeGenerator challengeGenerator;
+    late FirestorePostGenerator postGenerator;
+
+    setUp(() async {
+      container = ProviderContainer(
+        overrides: [
+          loggedInUserIdProvider.overrideWithValue(testingUserFirestoreId),
+          firestoreProvider.overrideWithValue(fakeFireStore),
+        ],
+      );
+      challengeGenerator = FirestoreChallengeGenerator();
+      postGenerator = FirestorePostGenerator();
+
+      await setUserFirestore(fakeFireStore, testingUserFirestore);
+
+      final post = postGenerator.generatePostAt(
+        userPosition1,
+      );
+      await setPostFirestore(post, fakeFireStore);
+    });
+
+    test("On challenge completion check centauri points refresh", () async {
+      // Check the initial number of centauri points
+      final centauriPointsBeforeChallengeCompletion = await container.read(
+        dynamicUserAvatarViewModelProvider(testingUserFirestoreId).future,
+      );
+      expect(
+        centauriPointsBeforeChallengeCompletion.centauriPoints,
+        testingUserData.centauriPoints,
+      );
+
+      // Generate a challenge
+      final challenge = challengeGenerator.generateChallenge(
+        false,
+        const Duration(hours: 2, minutes: 30),
+      );
+      await setChallenge(fakeFireStore, challenge, testingUserFirestoreId);
+
+      await container
+          .read(challengeViewModelProvider.notifier)
+          .completeChallenge(challenge.postId);
+
+      await Future.delayed(delayNeededForAsyncFunctionExecution);
+
+      // Check the final number of centauri points
+      final centauriPointsAfterChallengeCompletion = await container.read(
+        dynamicUserAvatarViewModelProvider(testingUserFirestoreId).future,
+      );
+      expect(
+        centauriPointsAfterChallengeCompletion.centauriPoints,
+        testingUserData.centauriPoints +
+            ChallengeRepositoryService.soloChallengeReward,
+      );
+    });
+  });
+}
diff --git a/test/viewmodels/user_avatar_view_model_unit_test.dart b/test/viewmodels/dynamic_user_avatar_view_model_unit_test.dart
similarity index 71%
rename from test/viewmodels/user_avatar_view_model_unit_test.dart
rename to test/viewmodels/dynamic_user_avatar_view_model_unit_test.dart
index a8906107..07bd8a27 100644
--- a/test/viewmodels/user_avatar_view_model_unit_test.dart
+++ b/test/viewmodels/dynamic_user_avatar_view_model_unit_test.dart
@@ -10,7 +10,7 @@ import "package:proxima/viewmodels/login_view_model.dart";
 import "../mocks/data/firestore_user.dart";
 
 void main() {
-  group("User Avatar ViewModel unit testing", () {
+  group("Dynamic User Avatar ViewModel unit testing", () {
     late FakeFirebaseFirestore fakeFireStore;
     late UserRepositoryService userRepo;
 
@@ -31,7 +31,8 @@ void main() {
       ];
     });
 
-    group("User Avatar display name provider unit testing without current user",
+    group(
+        "Dynamic User Avatar display name provider unit testing without current user",
         () {
       setUp(() async {
         container = ProviderContainer(
@@ -47,7 +48,7 @@ void main() {
         );
       });
     });
-    group("User Avatar display name provider unit testing", () {
+    group("Dynamic User Avatar display name provider unit testing", () {
       late List<UserFirestore> availableUsers;
 
       setUp(() async {
@@ -85,6 +86,30 @@ void main() {
           );
         }
       });
+
+      group("User Centauri points unit testing", () {
+        test("Find centauri points given null user id", () async {
+          final userAvatarDetails = await container.read(
+            dynamicUserAvatarViewModelProvider(null).future,
+          );
+          expect(
+            userAvatarDetails.centauriPoints,
+            availableUsers[0].data.centauriPoints,
+          );
+        });
+
+        test("Find centauri points given user id in available users", () async {
+          for (final user in availableUsers) {
+            final userAvatarDetails = await container.read(
+              dynamicUserAvatarViewModelProvider(user.uid).future,
+            );
+            expect(
+              userAvatarDetails.centauriPoints,
+              user.data.centauriPoints,
+            );
+          }
+        });
+      });
     });
   });
 }
diff --git a/test/viewmodels/post_comment_count_view_model_integration_test.dart b/test/viewmodels/post_comment_count_view_model_integration_test.dart
new file mode 100644
index 00000000..0678bae4
--- /dev/null
+++ b/test/viewmodels/post_comment_count_view_model_integration_test.dart
@@ -0,0 +1,134 @@
+import "package:collection/collection.dart";
+import "package:fake_cloud_firestore/fake_cloud_firestore.dart";
+import "package:flutter_test/flutter_test.dart";
+import "package:hooks_riverpod/hooks_riverpod.dart";
+import "package:mockito/mockito.dart";
+import "package:proxima/models/database/comment/comment_firestore.dart";
+import "package:proxima/models/database/post/post_firestore.dart";
+import "package:proxima/models/database/post/post_id_firestore.dart";
+import "package:proxima/services/database/comment/comment_repository_service.dart";
+import "package:proxima/services/database/firestore_service.dart";
+import "package:proxima/services/sensors/geolocation_service.dart";
+import "package:proxima/viewmodels/comments_view_model.dart";
+import "package:proxima/viewmodels/login_view_model.dart";
+import "package:proxima/viewmodels/post_comment_count_view_model.dart";
+import "package:proxima/viewmodels/user_comments_view_model.dart";
+
+import "../mocks/data/comment_data.dart";
+import "../mocks/data/firestore_post.dart";
+import "../mocks/data/firestore_user.dart";
+import "../mocks/data/geopoint.dart";
+import "../mocks/services/mock_geo_location_service.dart";
+import "../mocks/services/setup_firebase_mocks.dart";
+import "../utils/delay_async_func.dart";
+
+void main() {
+  late MockGeolocationService geoLocationService;
+  late FakeFirebaseFirestore fakeFireStore;
+  late ProviderContainer container;
+
+  late CommentRepositoryService commentRepository;
+
+  setUp(() {
+    setupFirebaseAuthMocks();
+
+    geoLocationService = MockGeolocationService();
+    fakeFireStore = FakeFirebaseFirestore();
+    when(geoLocationService.getCurrentPosition()).thenAnswer(
+      (_) async => userPosition0,
+    );
+
+    container = ProviderContainer(
+      overrides: [
+        geolocationServiceProvider.overrideWithValue(geoLocationService),
+        loggedInUserIdProvider.overrideWithValue(testingUserFirestoreId),
+        firestoreProvider.overrideWithValue(fakeFireStore),
+      ],
+    );
+
+    commentRepository = container.read(commentRepositoryServiceProvider);
+  });
+
+  Future<void> expectCommentCount(
+    PostIdFirestore postId,
+    int expectedCount,
+  ) async {
+    final actualCount = await container.read(
+      postCommentCountProvider(postId).future,
+    );
+    expect(actualCount, equals(expectedCount));
+  }
+
+  group("Comment count refresh", () {
+    const int startCommentCount = 5;
+    late PostFirestore post;
+    late List<CommentFirestore> comments;
+
+    setUp(() async {
+      // Create and add a post to the database
+      final postGenerator = FirestorePostGenerator();
+      post = postGenerator.generatePostAt(userPosition0);
+      await setPostFirestore(post, fakeFireStore);
+
+      // Create comments
+      final commentDataGenerator = CommentDataGenerator();
+      final commentDatas = List.generate(
+        startCommentCount,
+        (_) => commentDataGenerator.createMockCommentData(
+          ownerId: testingUserFirestoreId,
+        ),
+      ).toList();
+
+      // Add the comments to the database
+      final commentIds = await Future.wait(
+        commentDatas.map(
+          (commentData) => commentRepository.addComment(post.id, commentData),
+        ),
+      );
+
+      comments = commentIds
+          .mapIndexed(
+            (i, id) => CommentFirestore(id: id, data: commentDatas[i]),
+          )
+          .toList();
+    });
+
+    test("Refresh on comment list refresh", () async {
+      await expectCommentCount(post.id, startCommentCount);
+
+      // Add a new comment
+      final newComment = CommentDataGenerator().createMockCommentData();
+      await commentRepository.addComment(post.id, newComment);
+
+      // This should not have refreshed for now
+      await expectCommentCount(post.id, startCommentCount);
+
+      // Refresh the comment list
+      await container
+          .read(commentsViewModelProvider(post.id).notifier)
+          .refresh();
+      await Future.delayed(delayNeededForAsyncFunctionExecution);
+
+      // The comment count should now be updated
+      await expectCommentCount(post.id, startCommentCount + 1);
+    });
+
+    test("Refresh on comment deletion in view-model", () async {
+      await expectCommentCount(post.id, startCommentCount);
+
+      // Delete the post
+      final comment = comments.first;
+      final userCommentViewModel = container.read(
+        userCommentsViewModelProvider.notifier,
+      );
+      await userCommentViewModel.deleteComment(
+        post.id,
+        comment.id,
+      );
+      await Future.delayed(delayNeededForAsyncFunctionExecution);
+
+      // The comment count should now be 1 less
+      await expectCommentCount(post.id, startCommentCount - 1);
+    });
+  });
+}
diff --git a/test/viewmodels/posts_feed_view_model_integration_test.dart b/test/viewmodels/posts_feed_view_model_integration_test.dart
index f4a90635..6ed0a770 100644
--- a/test/viewmodels/posts_feed_view_model_integration_test.dart
+++ b/test/viewmodels/posts_feed_view_model_integration_test.dart
@@ -118,6 +118,7 @@ void main() {
           voteScore: postData.voteScore,
           ownerDisplayName: owner.data.displayName,
           ownerUsername: owner.data.username,
+          ownerUserID: owner.uid,
           ownerCentauriPoints: owner.data.centauriPoints,
           commentNumber: postData.commentCount,
           publicationDate: postData.publicationTime.toDate(),
@@ -217,6 +218,7 @@ void main() {
           voteScore: data.voteScore,
           ownerDisplayName: owner.data.displayName,
           ownerUsername: owner.data.username,
+          ownerUserID: owner.uid,
           ownerCentauriPoints: owner.data.centauriPoints,
           commentNumber: data.commentCount,
           publicationDate: data.publicationTime.toDate(),
diff --git a/test/viewmodels/posts_feed_view_model_unit_test.dart b/test/viewmodels/posts_feed_view_model_unit_test.dart
index 01b5b1c0..13a35ee9 100644
--- a/test/viewmodels/posts_feed_view_model_unit_test.dart
+++ b/test/viewmodels/posts_feed_view_model_unit_test.dart
@@ -118,6 +118,7 @@ void main() {
           commentNumber: post.data.commentCount,
           ownerDisplayName: owner.data.displayName,
           ownerUsername: owner.data.username,
+          ownerUserID: owner.uid,
           ownerCentauriPoints: owner.data.centauriPoints,
           publicationDate: post.data.publicationTime.toDate(),
           distance: 0,
@@ -176,6 +177,7 @@ void main() {
             commentNumber: post.data.commentCount,
             ownerDisplayName: owner.data.displayName,
             ownerUsername: owner.data.username,
+            ownerUserID: owner.uid,
             ownerCentauriPoints: owner.data.centauriPoints,
             publicationDate: post.data.publicationTime.toDate(),
             distance: 0,
@@ -242,6 +244,7 @@ void main() {
             commentNumber: post.data.commentCount,
             ownerDisplayName: owners[index].data.displayName,
             ownerUsername: owners[index].data.username,
+            ownerUserID: owners[index].uid,
             ownerCentauriPoints: owners[index].data.centauriPoints,
             publicationDate: post.data.publicationTime.toDate(),
             distance: 0,
@@ -321,6 +324,7 @@ void main() {
           commentNumber: post.data.commentCount,
           ownerDisplayName: owner.data.displayName,
           ownerUsername: owner.data.username,
+          ownerUserID: owner.uid,
           ownerCentauriPoints: owner.data.centauriPoints,
           publicationDate: post.data.publicationTime.toDate(),
           distance: 0,
diff --git a/test/views/pages/home/content/ranking/static_ranking_list_test.dart b/test/views/pages/home/content/ranking/static_ranking_list_test.dart
index 2e25c4b9..3a0d2a7e 100644
--- a/test/views/pages/home/content/ranking/static_ranking_list_test.dart
+++ b/test/views/pages/home/content/ranking/static_ranking_list_test.dart
@@ -1,20 +1,27 @@
 import "package:flutter/material.dart";
 import "package:flutter_test/flutter_test.dart";
+import "package:hooks_riverpod/hooks_riverpod.dart";
 import "package:proxima/views/components/content/user_profile_pop_up.dart";
 import "package:proxima/views/pages/home/content/ranking/components/ranking_card.dart";
 import "package:proxima/views/pages/home/content/ranking/components/ranking_list.dart";
 
 import "../../../../../mocks/data/ranking_data.dart";
+import "../../../../../mocks/overrides/override_dynamic_user_avatar_view_model.dart";
 
 void main() {
   group("Widgets display", () {
     testWidgets(
       "Display ranking elements",
       (tester) async {
-        final rankingListWidget = MaterialApp(
-          home: RankingList(
-            rankingDetails: mockRankingDetailsWithtestUser,
-            onRefresh: () async {},
+        final rankingListWidget = ProviderScope(
+          overrides: [
+            ...mockDynamicUserAvatarViewModelEmptyDisplayNameOverride,
+          ],
+          child: MaterialApp(
+            home: RankingList(
+              rankingDetails: mockRankingDetailsWithtestUser,
+              onRefresh: () async {},
+            ),
           ),
         );