diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2afd8623b2..a5f2be6092 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
-## 0.9.1 (unreleased)
+## 0.10.0 (unreleased)
 
-- Updated Polars to 0.38.3
+- Updated Polars to 0.39.0
 - Added support for writing JSON to string
 - Added support for writing Parquet to `StringIO`
 - Added support for cross joins
diff --git a/Cargo.lock b/Cargo.lock
index efd2419582..6aca1dfc32 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1251,7 +1251,7 @@ dependencies = [
  "jemallocator",
  "magnus",
  "mimalloc",
- "polars 0.38.3",
+ "polars 0.39.0",
  "polars-core",
  "polars-parquet",
  "polars-utils",
@@ -1261,9 +1261,9 @@ dependencies = [
 
 [[package]]
 name = "polars"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f01006048a264047d6cba081fed8e11adbd69c15956f9e53185a9ac4a541853c"
+checksum = "2dbcfc1444984ea01a2109c042b6413bbef2e147bb2a8ecb324237973a41ca56"
 dependencies = [
  "getrandom",
  "polars-arrow",
@@ -1282,9 +1282,9 @@ dependencies = [
 
 [[package]]
 name = "polars-arrow"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "25197f40d71f82b2f79bb394f03e555d3cc1ce4db1dd052c28318721c71e96ad"
+checksum = "a446c4f871cc92b0671116bf2550eb6037b3087486a6d94b0d4a25a900505ddc"
 dependencies = [
  "ahash",
  "atoi",
@@ -1330,9 +1330,9 @@ dependencies = [
 
 [[package]]
 name = "polars-compute"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c354515f73cdbbad03c2bf723fcd68e6825943b3ec503055abc8a8cb08ce46bb"
+checksum = "f18711721605134e04cff8bacee231b96ee148e00c7dfef720840c0362692bbe"
 dependencies = [
  "bytemuck",
  "either",
@@ -1346,9 +1346,9 @@ dependencies = [
 
 [[package]]
 name = "polars-core"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6f20d3c227186f74aa3c228c64ef72f5a15617322fed30b4323eaf53b25f8e7b"
+checksum = "7c2564d8383217bdc6de5a684d9df75a2cbedf23906d0df227d1ef638b6e3f95"
 dependencies = [
  "ahash",
  "bitflags 2.4.1",
@@ -1380,9 +1380,9 @@ dependencies = [
 
 [[package]]
 name = "polars-error"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d66dd0ce51f8bd620eb8bd376502fe68a2b1a446d5433ecd2e75270b0755ce76"
+checksum = "60fdc5165c4447e5afd7ca417b38dccc05ee189dcfabec11957a93e79016f5ab"
 dependencies = [
  "avro-schema",
  "polars-arrow-format",
@@ -1393,9 +1393,9 @@ dependencies = [
 
 [[package]]
 name = "polars-io"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b40bef2edcdc58394792c4d779465144283a09ff1836324e7b72df7978a6e992"
+checksum = "5e9e26cf2c62e29c638449f2c4beaf79fae19ebb21aa021bad621eb9cf50df31"
 dependencies = [
  "ahash",
  "async-trait",
@@ -1433,9 +1433,9 @@ dependencies = [
 
 [[package]]
 name = "polars-json"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ef86aca08f10ddc939fe95aabb44e1d2582dcb08b55d4dadb93353ce42adc248"
+checksum = "03d4a6674e24d521e0419553748721b1beb8c84665a23dcf6f2551f8199e8597"
 dependencies = [
  "ahash",
  "chrono",
@@ -1454,9 +1454,9 @@ dependencies = [
 
 [[package]]
 name = "polars-lazy"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c27df26a19d3092298d31d47614ad84dc330c106e38aa8cd53727cd91c07cf56"
+checksum = "459a2995976fe67b9a878398bd406b6fe8340d04591db1228a80cec8727a9b58"
 dependencies = [
  "ahash",
  "bitflags 2.4.1",
@@ -1478,9 +1478,9 @@ dependencies = [
 
 [[package]]
 name = "polars-ops"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f8a51c3bdc9e7c34196ff6f5c3cb17da134e5aafb1756aaf24b76c7118e63dc"
+checksum = "cd1358fa9f07d779bea1aba72c04e9809e8266a944d5297909391b47c7f4f174"
 dependencies = [
  "ahash",
  "aho-corasick",
@@ -1515,9 +1515,9 @@ dependencies = [
 
 [[package]]
 name = "polars-parquet"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b8824ee00fbbe83d69553f2711014c50361238d210ed81a7a297695b7db97d42"
+checksum = "5c436751e22b87cf301a99c4a7786a35eedf7436d2d40779e575fa16c9f8017c"
 dependencies = [
  "ahash",
  "async-stream",
@@ -1541,9 +1541,9 @@ dependencies = [
 
 [[package]]
 name = "polars-pipe"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0c5e2c1f14e81d60cfa9afe4e611a9bad9631a2cb7cd19b7c0094d0dc32f0231"
+checksum = "2a8f97a51fbe38f5c70e07fa3c585fc963674811b4ccddb6a13ae54b162c7943"
 dependencies = [
  "crossbeam-channel",
  "crossbeam-queue",
@@ -1566,14 +1566,15 @@ dependencies = [
 
 [[package]]
 name = "polars-plan"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ff48362bd1b078bbbec7e7ba9ec01fea58fee2887db22a8e3deaf78f322fa3c4"
+checksum = "1b6e66f9fa6b5f1c15db671d0f4a3713e15e49bd0d141b8e441d800a0b3cecee"
 dependencies = [
  "ahash",
  "bytemuck",
  "chrono",
  "chrono-tz",
+ "hashbrown 0.14.3",
  "once_cell",
  "percent-encoding",
  "polars-arrow",
@@ -1585,6 +1586,7 @@ dependencies = [
  "polars-time",
  "polars-utils",
  "rayon",
+ "recursive",
  "regex",
  "serde",
  "smartstring",
@@ -1594,9 +1596,9 @@ dependencies = [
 
 [[package]]
 name = "polars-row"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "63029da56ff6a720b190490bbc7b6263f9b72d1134311b1f381fc8d306d37770"
+checksum = "788c92dd5933c2891c827feb6b6247b3fcece866c873cbab8ea3431e19a710d0"
 dependencies = [
  "bytemuck",
  "polars-arrow",
@@ -1606,9 +1608,9 @@ dependencies = [
 
 [[package]]
 name = "polars-sql"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3652c362959f608d1297196b973d1e3acb508a9562b886ac39bf7606b841052b"
+checksum = "aca24b4cbf8718a3579f82200c83f93bc75a00656bc267fc503e5232bcd81ead"
 dependencies = [
  "hex",
  "polars-arrow",
@@ -1624,9 +1626,9 @@ dependencies = [
 
 [[package]]
 name = "polars-time"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "86eb74ea6ddfe675aa5c3f33c00dadbe2b85f0e8e3887b85db1fd5a3397267fd"
+checksum = "582b0775bcc72d9b5cd0eab876728b75616614c04352653135a9a81dc935fb7f"
 dependencies = [
  "atoi",
  "chrono",
@@ -1645,9 +1647,9 @@ dependencies = [
 
 [[package]]
 name = "polars-utils"
-version = "0.38.3"
+version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "694656a7d2b0cd8f07660dbc8d0fb7a81066ff57a452264907531d805c1e58c4"
+checksum = "073417d96545a1f1ed0ed112bb2e99a0f016182b4fe112151f4b1b57abb52000"
 dependencies = [
  "ahash",
  "bytemuck",
@@ -1659,6 +1661,7 @@ dependencies = [
  "raw-cpuid",
  "rayon",
  "smartstring",
+ "stacker",
  "sysinfo",
  "version_check",
 ]
@@ -1678,6 +1681,15 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "psm"
+version = "0.1.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5787f7cda34e3033a72192c018bc5883100330f362ef279a8cbccfce8bb4e874"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.35"
@@ -1786,6 +1798,26 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a35802679f07360454b418a5d1735c89716bde01d35b1560fc953c1415a0b3bb"
 
+[[package]]
+name = "recursive"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0786a43debb760f491b1bc0269fe5e84155353c67482b9e60d0cfb596054b43e"
+dependencies = [
+ "recursive-proc-macro-impl",
+ "stacker",
+]
+
+[[package]]
+name = "recursive-proc-macro-impl"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "76009fbe0614077fc1a2ce255e3a1881a2e3a3527097d5dc6d8212c585e7e38b"
+dependencies = [
+ "quote",
+ "syn 2.0.46",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.4.1"
@@ -2012,6 +2044,19 @@ dependencies = [
  "log",
 ]
 
+[[package]]
+name = "stacker"
+version = "0.1.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c886bd4480155fd3ef527d45e9ac8dd7118a898a46530b7b94c3e21866259fce"
+dependencies = [
+ "cc",
+ "cfg-if",
+ "libc",
+ "psm",
+ "winapi",
+]
+
 [[package]]
 name = "static_assertions"
 version = "1.1.0"
diff --git a/ext/polars/Cargo.toml b/ext/polars/Cargo.toml
index 1ae9b4e9ea..e1b24c05a8 100644
--- a/ext/polars/Cargo.toml
+++ b/ext/polars/Cargo.toml
@@ -15,14 +15,14 @@ ahash = "0.8"
 chrono = "0.4"
 either = "1.8"
 magnus = "0.6"
-polars-core = "=0.38.3"
-polars-parquet = "=0.38.3"
-polars-utils = "=0.38.3"
+polars-core = "=0.39.0"
+polars-parquet = "=0.39.0"
+polars-utils = "=0.39.0"
 serde_json = "1"
 smartstring = "1"
 
 [dependencies.polars]
-version = "=0.38.3"
+version = "=0.39.0"
 features = [
     "abs",
     "approx_unique",
diff --git a/ext/polars/src/conversion/anyvalue.rs b/ext/polars/src/conversion/anyvalue.rs
index 5659208880..5e8782913e 100644
--- a/ext/polars/src/conversion/anyvalue.rs
+++ b/ext/polars/src/conversion/anyvalue.rs
@@ -3,8 +3,8 @@ use magnus::{
     class, prelude::*, r_hash::ForEach, Float, Integer, IntoValue, RArray, RHash, RString, Ruby,
     TryConvert, Value,
 };
-use polars::frame::row::any_values_to_dtype;
 use polars::prelude::*;
+use polars_core::utils::any_values_to_supertype_and_n_dtypes;
 
 use super::{struct_dict, ObjectValue, Wrap};
 
@@ -120,7 +120,8 @@ impl<'s> TryConvert for Wrap<AnyValue<'s>> {
                     avs.push(Wrap::<AnyValue>::try_convert(item?)?.0)
                 }
 
-                let (dtype, _n_types) = any_values_to_dtype(&avs).map_err(RbPolarsErr::from)?;
+                let (dtype, _n_types) =
+                    any_values_to_supertype_and_n_dtypes(&avs).map_err(RbPolarsErr::from)?;
 
                 // push the rest
                 avs.reserve(list.len());
diff --git a/ext/polars/src/expr/array.rs b/ext/polars/src/expr/array.rs
index 041d4becde..c59baf97b9 100644
--- a/ext/polars/src/expr/array.rs
+++ b/ext/polars/src/expr/array.rs
@@ -59,8 +59,12 @@ impl RbExpr {
         self.inner.clone().arr().arg_max().into()
     }
 
-    pub fn arr_get(&self, index: &RbExpr) -> Self {
-        self.inner.clone().arr().get(index.inner.clone()).into()
+    pub fn arr_get(&self, index: &RbExpr, null_on_oob: bool) -> Self {
+        self.inner
+            .clone()
+            .arr()
+            .get(index.inner.clone(), null_on_oob)
+            .into()
     }
 
     pub fn arr_join(&self, separator: &RbExpr, ignore_nulls: bool) -> Self {
diff --git a/ext/polars/src/expr/general.rs b/ext/polars/src/expr/general.rs
index 98f91c8d72..bbd876ba35 100644
--- a/ext/polars/src/expr/general.rs
+++ b/ext/polars/src/expr/general.rs
@@ -267,7 +267,7 @@ impl RbExpr {
     pub fn sort_with(&self, descending: bool, nulls_last: bool) -> Self {
         self.clone()
             .inner
-            .sort_with(SortOptions {
+            .sort(SortOptions {
                 descending,
                 nulls_last,
                 multithreaded: true,
@@ -323,9 +323,28 @@ impl RbExpr {
         self.clone().inner.gather(idx.inner.clone()).into()
     }
 
-    pub fn sort_by(&self, by: RArray, reverse: Vec<bool>) -> RbResult<Self> {
+    pub fn sort_by(
+        &self,
+        by: RArray,
+        descending: Vec<bool>,
+        nulls_last: bool,
+        multithreaded: bool,
+        maintain_order: bool,
+    ) -> RbResult<Self> {
         let by = rb_exprs_to_exprs(by)?;
-        Ok(self.clone().inner.sort_by(by, reverse).into())
+        Ok(self
+            .clone()
+            .inner
+            .sort_by(
+                by,
+                SortMultipleOptions {
+                    descending,
+                    nulls_last,
+                    multithreaded,
+                    maintain_order,
+                },
+            )
+            .into())
     }
 
     pub fn backward_fill(&self, limit: FillNullLimit) -> Self {
diff --git a/ext/polars/src/expr/list.rs b/ext/polars/src/expr/list.rs
index 7b458be7a4..55c8490023 100644
--- a/ext/polars/src/expr/list.rs
+++ b/ext/polars/src/expr/list.rs
@@ -51,8 +51,12 @@ impl RbExpr {
             .into()
     }
 
-    pub fn list_get(&self, index: &RbExpr) -> Self {
-        self.inner.clone().list().get(index.inner.clone()).into()
+    pub fn list_get(&self, index: &RbExpr, null_on_oob: bool) -> Self {
+        self.inner
+            .clone()
+            .list()
+            .get(index.inner.clone(), null_on_oob)
+            .into()
     }
 
     pub fn list_join(&self, separator: &RbExpr, ignore_nulls: bool) -> Self {
diff --git a/ext/polars/src/expr/string.rs b/ext/polars/src/expr/string.rs
index 1dd9745647..6240efa38d 100644
--- a/ext/polars/src/expr/string.rs
+++ b/ext/polars/src/expr/string.rs
@@ -244,12 +244,12 @@ impl RbExpr {
             .into()
     }
 
-    pub fn str_to_integer(&self, base: u32, strict: bool) -> Self {
+    pub fn str_to_integer(&self, base: &Self, strict: bool) -> Self {
         self.inner
             .clone()
             .str()
-            .to_integer(base, strict)
-            .with_fmt("str.parse_int")
+            .to_integer(base.inner.clone(), strict)
+            .with_fmt("str.to_integer")
             .into()
     }
 
diff --git a/ext/polars/src/functions/lazy.rs b/ext/polars/src/functions/lazy.rs
index afa0abdcbe..97e34b87f8 100644
--- a/ext/polars/src/functions/lazy.rs
+++ b/ext/polars/src/functions/lazy.rs
@@ -55,9 +55,24 @@ pub fn rolling_cov(
     .into()
 }
 
-pub fn arg_sort_by(by: RArray, descending: Vec<bool>) -> RbResult<RbExpr> {
+pub fn arg_sort_by(
+    by: RArray,
+    descending: Vec<bool>,
+    nulls_last: bool,
+    multithreaded: bool,
+    maintain_order: bool,
+) -> RbResult<RbExpr> {
     let by = rb_exprs_to_exprs(by)?;
-    Ok(dsl::arg_sort_by(by, &descending).into())
+    Ok(dsl::arg_sort_by(
+        by,
+        SortMultipleOptions {
+            descending,
+            nulls_last,
+            multithreaded,
+            maintain_order,
+        },
+    )
+    .into())
 }
 
 pub fn arg_where(condition: &RbExpr) -> RbExpr {
diff --git a/ext/polars/src/lazyframe/mod.rs b/ext/polars/src/lazyframe/mod.rs
index b53c4a743c..5e3c08e8ee 100644
--- a/ext/polars/src/lazyframe/mod.rs
+++ b/ext/polars/src/lazyframe/mod.rs
@@ -1,5 +1,5 @@
 use magnus::{IntoValue, RArray, RHash, TryConvert, Value};
-use polars::io::RowIndex;
+use polars::io::{HiveOptions, RowIndex};
 use polars::lazy::frame::LazyFrame;
 use polars::prelude::*;
 use std::cell::RefCell;
@@ -148,7 +148,8 @@ impl RbLazyFrame {
 
     #[allow(clippy::too_many_arguments)]
     pub fn new_from_parquet(
-        path: String,
+        path: Option<PathBuf>,
+        paths: Vec<PathBuf>,
         n_rows: Option<usize>,
         cache: bool,
         parallel: Wrap<ParallelStrategy>,
@@ -157,21 +158,43 @@ impl RbLazyFrame {
         low_memory: bool,
         use_statistics: bool,
         hive_partitioning: bool,
+        hive_schema: Option<Wrap<Schema>>,
     ) -> RbResult<Self> {
+        let parallel = parallel.0;
+        let hive_schema = hive_schema.map(|s| Arc::new(s.0));
+
+        let first_path = if let Some(path) = &path {
+            path
+        } else {
+            paths
+                .first()
+                .ok_or_else(|| RbValueError::new_err("expected a path argument".to_string()))?
+        };
+
         let row_index = row_index.map(|(name, offset)| RowIndex { name, offset });
+        let hive_options = HiveOptions {
+            enabled: hive_partitioning,
+            schema: hive_schema,
+        };
+
         let args = ScanArgsParquet {
             n_rows,
             cache,
-            parallel: parallel.0,
+            parallel,
             rechunk,
             row_index,
             low_memory,
-            // TODO support cloud options
             cloud_options: None,
             use_statistics,
-            hive_partitioning,
+            hive_options,
         };
-        let lf = LazyFrame::scan_parquet(path, args).map_err(RbPolarsErr::from)?;
+
+        let lf = if path.is_some() {
+            LazyFrame::scan_parquet(first_path, args)
+        } else {
+            LazyFrame::scan_parquet_files(Arc::from(paths), args)
+        }
+        .map_err(RbPolarsErr::from)?;
         Ok(lf.into())
     }
 
@@ -189,7 +212,8 @@ impl RbLazyFrame {
             cache,
             rechunk,
             row_index,
-            memmap: memory_map,
+            memory_map,
+            cloud_options: None,
         };
         let lf = LazyFrame::scan_ipc(path, args).map_err(RbPolarsErr::from)?;
         Ok(lf.into())
@@ -246,17 +270,18 @@ impl RbLazyFrame {
     pub fn sort(
         &self,
         by_column: String,
-        reverse: bool,
+        descending: bool,
         nulls_last: bool,
         maintain_order: bool,
+        multithreaded: bool,
     ) -> Self {
         let ldf = self.ldf.clone();
         ldf.sort(
-            &by_column,
-            SortOptions {
-                descending: reverse,
+            [&by_column],
+            SortMultipleOptions {
+                descending: vec![descending],
                 nulls_last,
-                multithreaded: true,
+                multithreaded,
                 maintain_order,
             },
         )
@@ -265,15 +290,24 @@ impl RbLazyFrame {
 
     pub fn sort_by_exprs(
         &self,
-        by_column: RArray,
-        reverse: Vec<bool>,
+        by: RArray,
+        descending: Vec<bool>,
         nulls_last: bool,
         maintain_order: bool,
+        multithreaded: bool,
     ) -> RbResult<Self> {
         let ldf = self.ldf.clone();
-        let exprs = rb_exprs_to_exprs(by_column)?;
+        let exprs = rb_exprs_to_exprs(by)?;
         Ok(ldf
-            .sort_by_exprs(exprs, reverse, nulls_last, maintain_order)
+            .sort_by_exprs(
+                exprs,
+                SortMultipleOptions {
+                    descending,
+                    nulls_last,
+                    maintain_order,
+                    multithreaded,
+                },
+            )
             .into())
     }
 
@@ -432,7 +466,7 @@ impl RbLazyFrame {
         let closed_window = closed.0;
         let ldf = self.ldf.clone();
         let by = rb_exprs_to_exprs(by)?;
-        let lazy_gb = ldf.group_by_rolling(
+        let lazy_gb = ldf.rolling(
             index_column.inner.clone(),
             by,
             RollingGroupOptions {
diff --git a/ext/polars/src/lib.rs b/ext/polars/src/lib.rs
index 9954e0a978..6731459630 100644
--- a/ext/polars/src/lib.rs
+++ b/ext/polars/src/lib.rs
@@ -213,7 +213,7 @@ fn init(ruby: &Ruby) -> RbResult<()> {
     class.define_method("arg_min", method!(RbExpr::arg_min, 0))?;
     class.define_method("search_sorted", method!(RbExpr::search_sorted, 2))?;
     class.define_method("gather", method!(RbExpr::gather, 1))?;
-    class.define_method("sort_by", method!(RbExpr::sort_by, 2))?;
+    class.define_method("sort_by", method!(RbExpr::sort_by, 5))?;
     class.define_method("backward_fill", method!(RbExpr::backward_fill, 1))?;
     class.define_method("forward_fill", method!(RbExpr::forward_fill, 1))?;
     class.define_method("shift", method!(RbExpr::shift, 2))?;
@@ -312,7 +312,7 @@ fn init(ruby: &Ruby) -> RbResult<()> {
     class.define_method("arr_reverse", method!(RbExpr::arr_reverse, 0))?;
     class.define_method("arr_arg_min", method!(RbExpr::arr_arg_min, 0))?;
     class.define_method("arr_arg_max", method!(RbExpr::arr_arg_max, 0))?;
-    class.define_method("arr_get", method!(RbExpr::arr_get, 1))?;
+    class.define_method("arr_get", method!(RbExpr::arr_get, 2))?;
     class.define_method("arr_join", method!(RbExpr::arr_join, 2))?;
     class.define_method("arr_contains", method!(RbExpr::arr_contains, 1))?;
     class.define_method("arr_count_matches", method!(RbExpr::arr_count_matches, 1))?;
@@ -448,7 +448,7 @@ fn init(ruby: &Ruby) -> RbResult<()> {
     class.define_method("list_sort", method!(RbExpr::list_sort, 1))?;
     class.define_method("list_reverse", method!(RbExpr::list_reverse, 0))?;
     class.define_method("list_unique", method!(RbExpr::list_unique, 1))?;
-    class.define_method("list_get", method!(RbExpr::list_get, 1))?;
+    class.define_method("list_get", method!(RbExpr::list_get, 2))?;
     class.define_method("list_join", method!(RbExpr::list_join, 2))?;
     class.define_method("list_arg_min", method!(RbExpr::list_arg_min, 0))?;
     class.define_method("list_arg_max", method!(RbExpr::list_arg_max, 0))?;
@@ -554,7 +554,7 @@ fn init(ruby: &Ruby) -> RbResult<()> {
     class.define_singleton_method("arctan2d", function!(functions::lazy::arctan2d, 2))?;
     class.define_singleton_method("rolling_corr", function!(functions::lazy::rolling_corr, 5))?;
     class.define_singleton_method("rolling_cov", function!(functions::lazy::rolling_cov, 5))?;
-    class.define_singleton_method("arg_sort_by", function!(functions::lazy::arg_sort_by, 2))?;
+    class.define_singleton_method("arg_sort_by", function!(functions::lazy::arg_sort_by, 5))?;
     class.define_singleton_method("when", function!(functions::whenthen::when, 1))?;
     class.define_singleton_method("concat_str", function!(functions::lazy::concat_str, 3))?;
     class.define_singleton_method("concat_list", function!(functions::lazy::concat_list, 1))?;
@@ -689,7 +689,7 @@ fn init(ruby: &Ruby) -> RbResult<()> {
     class.define_singleton_method("new_from_csv", function!(RbLazyFrame::new_from_csv, -1))?;
     class.define_singleton_method(
         "new_from_parquet",
-        function!(RbLazyFrame::new_from_parquet, 9),
+        function!(RbLazyFrame::new_from_parquet, 11),
     )?;
     class.define_singleton_method("new_from_ipc", function!(RbLazyFrame::new_from_ipc, 6))?;
     class.define_method("write_json", method!(RbLazyFrame::write_json, 1))?;
@@ -702,8 +702,8 @@ fn init(ruby: &Ruby) -> RbResult<()> {
         "optimization_toggle",
         method!(RbLazyFrame::optimization_toggle, 9),
     )?;
-    class.define_method("sort", method!(RbLazyFrame::sort, 4))?;
-    class.define_method("sort_by_exprs", method!(RbLazyFrame::sort_by_exprs, 4))?;
+    class.define_method("sort", method!(RbLazyFrame::sort, 5))?;
+    class.define_method("sort_by_exprs", method!(RbLazyFrame::sort_by_exprs, 5))?;
     class.define_method("cache", method!(RbLazyFrame::cache, 0))?;
     class.define_method("collect", method!(RbLazyFrame::collect, 0))?;
     class.define_method("sink_parquet", method!(RbLazyFrame::sink_parquet, 7))?;
@@ -835,7 +835,7 @@ fn init(ruby: &Ruby) -> RbResult<()> {
     class.define_method("mul", method!(RbSeries::mul, 1))?;
     class.define_method("div", method!(RbSeries::div, 1))?;
     class.define_method("rem", method!(RbSeries::rem, 1))?;
-    class.define_method("sort", method!(RbSeries::sort, 2))?;
+    class.define_method("sort", method!(RbSeries::sort, 3))?;
     class.define_method("value_counts", method!(RbSeries::value_counts, 1))?;
     class.define_method("any", method!(RbSeries::any, 1))?;
     class.define_method("all", method!(RbSeries::all, 1))?;
diff --git a/ext/polars/src/map/dataframe.rs b/ext/polars/src/map/dataframe.rs
index 277482a40e..3bcffe312b 100644
--- a/ext/polars/src/map/dataframe.rs
+++ b/ext/polars/src/map/dataframe.rs
@@ -265,9 +265,9 @@ pub fn apply_lambda_with_rows_output<'a>(
                         // to the row. Before we mutate the row buf again, the reference is dropped.
                         // we only cannot prove it to the compiler.
                         // we still do this because it saves a Vec allocation in a hot loop.
-                        unsafe { &*ptr }
+                        Ok(unsafe { &*ptr })
                     }
-                    None => &null_row,
+                    None => Ok(&null_row),
                 }
             }
             Err(e) => panic!("ruby function failed {}", e),
@@ -277,22 +277,30 @@ pub fn apply_lambda_with_rows_output<'a>(
     // first rows for schema inference
     let mut buf = Vec::with_capacity(inference_size);
     buf.push(first_value);
-    buf.extend((&mut row_iter).take(inference_size).cloned());
-    let schema = rows_to_schema_first_non_null(&buf, Some(50));
+    for v in (&mut row_iter).take(inference_size) {
+        buf.push(v?.clone());
+    }
+
+    let schema = rows_to_schema_first_non_null(&buf, Some(50))?;
 
     if init_null_count > 0 {
         // Safety: we know the iterators size
         let iter = unsafe {
             (0..init_null_count)
-                .map(|_| &null_row)
-                .chain(buf.iter())
+                .map(|_| Ok(&null_row))
+                .chain(buf.iter().map(Ok))
                 .chain(row_iter)
                 .trust_my_length(df.height())
         };
-        DataFrame::from_rows_iter_and_schema(iter, &schema)
+        DataFrame::try_from_rows_iter_and_schema(iter, &schema)
     } else {
         // Safety: we know the iterators size
-        let iter = unsafe { buf.iter().chain(row_iter).trust_my_length(df.height()) };
-        DataFrame::from_rows_iter_and_schema(iter, &schema)
+        let iter = unsafe {
+            buf.iter()
+                .map(Ok)
+                .chain(row_iter)
+                .trust_my_length(df.height())
+        };
+        DataFrame::try_from_rows_iter_and_schema(iter, &schema)
     }
 }
diff --git a/ext/polars/src/series/mod.rs b/ext/polars/src/series/mod.rs
index 3cb8082abc..36a8276018 100644
--- a/ext/polars/src/series/mod.rs
+++ b/ext/polars/src/series/mod.rs
@@ -233,8 +233,18 @@ impl RbSeries {
         }
     }
 
-    pub fn sort(&self, descending: bool, nulls_last: bool) -> Self {
-        (self.series.borrow_mut().sort(descending, nulls_last)).into()
+    pub fn sort(&self, descending: bool, nulls_last: bool, multithreaded: bool) -> RbResult<Self> {
+        Ok(self
+            .series
+            .borrow_mut()
+            .sort(
+                SortOptions::default()
+                    .with_order_descending(descending)
+                    .with_nulls_last(nulls_last)
+                    .with_multithreaded(multithreaded),
+            )
+            .map_err(RbPolarsErr::from)?
+            .into())
     }
 
     pub fn value_counts(&self, sorted: bool) -> RbResult<RbDataFrame> {
diff --git a/lib/polars/array_expr.rb b/lib/polars/array_expr.rb
index fdbc07f332..dccca199c6 100644
--- a/lib/polars/array_expr.rb
+++ b/lib/polars/array_expr.rb
@@ -353,9 +353,9 @@ def arg_max
     #   # │ [4, 5, 6]     ┆ -2  ┆ 5    │
     #   # │ [7, 8, 9]     ┆ 4   ┆ null │
     #   # └───────────────┴─────┴──────┘
-    def get(index)
+    def get(index, null_on_oob: true)
       index = Utils.parse_as_expression(index)
-      Utils.wrap_expr(_rbexpr.arr_get(index))
+      Utils.wrap_expr(_rbexpr.arr_get(index, null_on_oob))
     end
 
     # Get the first value of the sub-arrays.
diff --git a/lib/polars/data_frame.rb b/lib/polars/data_frame.rb
index afd82dddeb..96cbdcecf1 100644
--- a/lib/polars/data_frame.rb
+++ b/lib/polars/data_frame.rb
@@ -2214,12 +2214,13 @@ def group_by_rolling(
     #     closed: "right"
     #   ).agg(Polars.col("A").alias("A_agg_list"))
     #   # =>
-    #   # shape: (3, 4)
+    #   # shape: (4, 4)
     #   # ┌─────────────────┬─────────────────┬─────┬─────────────────┐
     #   # │ _lower_boundary ┆ _upper_boundary ┆ idx ┆ A_agg_list      │
     #   # │ ---             ┆ ---             ┆ --- ┆ ---             │
     #   # │ i64             ┆ i64             ┆ i64 ┆ list[str]       │
     #   # ╞═════════════════╪═════════════════╪═════╪═════════════════╡
+    #   # │ -2              ┆ 1               ┆ -2  ┆ ["A", "A"]      │
     #   # │ 0               ┆ 3               ┆ 0   ┆ ["A", "B", "B"] │
     #   # │ 2               ┆ 5               ┆ 2   ┆ ["B", "B", "C"] │
     #   # │ 4               ┆ 7               ┆ 4   ┆ ["C"]           │
@@ -2674,26 +2675,26 @@ def apply(return_dtype: nil, inference_size: 256, &f)
     #   # ┌─────┬─────┬───────────┐
     #   # │ a   ┆ b   ┆ b_squared │
     #   # │ --- ┆ --- ┆ ---       │
-    #   # │ i64 ┆ i64 ┆ f64       │
+    #   # │ i64 ┆ i64 ┆ i64       │
     #   # ╞═════╪═════╪═══════════╡
-    #   # │ 1   ┆ 2   ┆ 4.0       │
-    #   # │ 3   ┆ 4   ┆ 16.0      │
-    #   # │ 5   ┆ 6   ┆ 36.0      │
+    #   # │ 1   ┆ 2   ┆ 4         │
+    #   # │ 3   ┆ 4   ┆ 16        │
+    #   # │ 5   ┆ 6   ┆ 36        │
     #   # └─────┴─────┴───────────┘
     #
     # @example Replaced
     #   df.with_column(Polars.col("a") ** 2)
     #   # =>
     #   # shape: (3, 2)
-    #   # ┌──────┬─────┐
-    #   # │ a    ┆ b   │
-    #   # │ ---  ┆ --- │
-    #   # │ f64  ┆ i64 │
-    #   # ╞══════╪═════╡
-    #   # │ 1.0  ┆ 2   │
-    #   # │ 9.0  ┆ 4   │
-    #   # │ 25.0 ┆ 6   │
-    #   # └──────┴─────┘
+    #   # ┌─────┬─────┐
+    #   # │ a   ┆ b   │
+    #   # │ --- ┆ --- │
+    #   # │ i64 ┆ i64 │
+    #   # ╞═════╪═════╡
+    #   # │ 1   ┆ 2   │
+    #   # │ 9   ┆ 4   │
+    #   # │ 25  ┆ 6   │
+    #   # └─────┴─────┘
     def with_column(column)
       lazy
         .with_column(column)
@@ -3788,16 +3789,16 @@ def select(*exprs, **named_exprs)
     #   df.with_columns((Polars.col("a") ** 2).alias("a^2"))
     #   # =>
     #   # shape: (4, 4)
-    #   # ┌─────┬──────┬───────┬──────┐
-    #   # │ a   ┆ b    ┆ c     ┆ a^2  │
-    #   # │ --- ┆ ---  ┆ ---   ┆ ---  │
-    #   # │ i64 ┆ f64  ┆ bool  ┆ f64  │
-    #   # ╞═════╪══════╪═══════╪══════╡
-    #   # │ 1   ┆ 0.5  ┆ true  ┆ 1.0  │
-    #   # │ 2   ┆ 4.0  ┆ true  ┆ 4.0  │
-    #   # │ 3   ┆ 10.0 ┆ false ┆ 9.0  │
-    #   # │ 4   ┆ 13.0 ┆ true  ┆ 16.0 │
-    #   # └─────┴──────┴───────┴──────┘
+    #   # ┌─────┬──────┬───────┬─────┐
+    #   # │ a   ┆ b    ┆ c     ┆ a^2 │
+    #   # │ --- ┆ ---  ┆ ---   ┆ --- │
+    #   # │ i64 ┆ f64  ┆ bool  ┆ i64 │
+    #   # ╞═════╪══════╪═══════╪═════╡
+    #   # │ 1   ┆ 0.5  ┆ true  ┆ 1   │
+    #   # │ 2   ┆ 4.0  ┆ true  ┆ 4   │
+    #   # │ 3   ┆ 10.0 ┆ false ┆ 9   │
+    #   # │ 4   ┆ 13.0 ┆ true  ┆ 16  │
+    #   # └─────┴──────┴───────┴─────┘
     #
     # @example Added columns will replace existing columns with the same name.
     #   df.with_columns(Polars.col("a").cast(Polars::Float64))
@@ -3824,16 +3825,16 @@ def select(*exprs, **named_exprs)
     #   )
     #   # =>
     #   # shape: (4, 6)
-    #   # ┌─────┬──────┬───────┬──────┬──────┬───────┐
-    #   # │ a   ┆ b    ┆ c     ┆ a^2  ┆ b/2  ┆ not c │
-    #   # │ --- ┆ ---  ┆ ---   ┆ ---  ┆ ---  ┆ ---   │
-    #   # │ i64 ┆ f64  ┆ bool  ┆ f64  ┆ f64  ┆ bool  │
-    #   # ╞═════╪══════╪═══════╪══════╪══════╪═══════╡
-    #   # │ 1   ┆ 0.5  ┆ true  ┆ 1.0  ┆ 0.25 ┆ false │
-    #   # │ 2   ┆ 4.0  ┆ true  ┆ 4.0  ┆ 2.0  ┆ false │
-    #   # │ 3   ┆ 10.0 ┆ false ┆ 9.0  ┆ 5.0  ┆ true  │
-    #   # │ 4   ┆ 13.0 ┆ true  ┆ 16.0 ┆ 6.5  ┆ false │
-    #   # └─────┴──────┴───────┴──────┴──────┴───────┘
+    #   # ┌─────┬──────┬───────┬─────┬──────┬───────┐
+    #   # │ a   ┆ b    ┆ c     ┆ a^2 ┆ b/2  ┆ not c │
+    #   # │ --- ┆ ---  ┆ ---   ┆ --- ┆ ---  ┆ ---   │
+    #   # │ i64 ┆ f64  ┆ bool  ┆ i64 ┆ f64  ┆ bool  │
+    #   # ╞═════╪══════╪═══════╪═════╪══════╪═══════╡
+    #   # │ 1   ┆ 0.5  ┆ true  ┆ 1   ┆ 0.25 ┆ false │
+    #   # │ 2   ┆ 4.0  ┆ true  ┆ 4   ┆ 2.0  ┆ false │
+    #   # │ 3   ┆ 10.0 ┆ false ┆ 9   ┆ 5.0  ┆ true  │
+    #   # │ 4   ┆ 13.0 ┆ true  ┆ 16  ┆ 6.5  ┆ false │
+    #   # └─────┴──────┴───────┴─────┴──────┴───────┘
     #
     # @example Multiple columns also can be added using positional arguments instead of a list.
     #   df.with_columns(
@@ -3843,16 +3844,16 @@ def select(*exprs, **named_exprs)
     #   )
     #   # =>
     #   # shape: (4, 6)
-    #   # ┌─────┬──────┬───────┬──────┬──────┬───────┐
-    #   # │ a   ┆ b    ┆ c     ┆ a^2  ┆ b/2  ┆ not c │
-    #   # │ --- ┆ ---  ┆ ---   ┆ ---  ┆ ---  ┆ ---   │
-    #   # │ i64 ┆ f64  ┆ bool  ┆ f64  ┆ f64  ┆ bool  │
-    #   # ╞═════╪══════╪═══════╪══════╪══════╪═══════╡
-    #   # │ 1   ┆ 0.5  ┆ true  ┆ 1.0  ┆ 0.25 ┆ false │
-    #   # │ 2   ┆ 4.0  ┆ true  ┆ 4.0  ┆ 2.0  ┆ false │
-    #   # │ 3   ┆ 10.0 ┆ false ┆ 9.0  ┆ 5.0  ┆ true  │
-    #   # │ 4   ┆ 13.0 ┆ true  ┆ 16.0 ┆ 6.5  ┆ false │
-    #   # └─────┴──────┴───────┴──────┴──────┴───────┘
+    #   # ┌─────┬──────┬───────┬─────┬──────┬───────┐
+    #   # │ a   ┆ b    ┆ c     ┆ a^2 ┆ b/2  ┆ not c │
+    #   # │ --- ┆ ---  ┆ ---   ┆ --- ┆ ---  ┆ ---   │
+    #   # │ i64 ┆ f64  ┆ bool  ┆ i64 ┆ f64  ┆ bool  │
+    #   # ╞═════╪══════╪═══════╪═════╪══════╪═══════╡
+    #   # │ 1   ┆ 0.5  ┆ true  ┆ 1   ┆ 0.25 ┆ false │
+    #   # │ 2   ┆ 4.0  ┆ true  ┆ 4   ┆ 2.0  ┆ false │
+    #   # │ 3   ┆ 10.0 ┆ false ┆ 9   ┆ 5.0  ┆ true  │
+    #   # │ 4   ┆ 13.0 ┆ true  ┆ 16  ┆ 6.5  ┆ false │
+    #   # └─────┴──────┴───────┴─────┴──────┴───────┘
     #
     # @example Use keyword arguments to easily name your expression inputs.
     #   df.with_columns(
diff --git a/lib/polars/expr.rb b/lib/polars/expr.rb
index bcd9caafec..d25095534a 100644
--- a/lib/polars/expr.rb
+++ b/lib/polars/expr.rb
@@ -1544,16 +1544,14 @@ def search_sorted(element, side: "any")
     #   # │ one   │
     #   # │ two   │
     #   # └───────┘
-    def sort_by(by, reverse: false)
-      if !by.is_a?(::Array)
-        by = [by]
-      end
+    def sort_by(by, *more_by, reverse: false, nulls_last: false, multithreaded: true, maintain_order: false)
+      by = Utils.parse_as_list_of_expressions(by, *more_by)
       if !reverse.is_a?(::Array)
         reverse = [reverse]
+      elsif by.length != reverse.length
+        raise ArgumentError, "the length of `reverse` (#{reverse.length}) does not match the length of `by` (#{by.length})"
       end
-      by = Utils.selection_to_rbexpr_list(by)
-
-      _from_rbexpr(_rbexpr.sort_by(by, reverse))
+      _from_rbexpr(_rbexpr.sort_by(by, reverse, nulls_last, multithreaded, maintain_order))
     end
 
     # Take values by index.
@@ -3515,20 +3513,23 @@ def truediv(other)
     # @return [Expr]
     #
     # @example
-    #   df = Polars::DataFrame.new({"foo" => [1, 2, 3, 4]})
-    #   df.select(Polars.col("foo").pow(3))
+    #   df = Polars::DataFrame.new({"x" => [1, 2, 4, 8]})
+    #   df.with_columns(
+    #     Polars.col("x").pow(3).alias("cube"),
+    #     Polars.col("x").pow(Polars.col("x").log(2)).alias("x ** xlog2")
+    #   )
     #   # =>
-    #   # shape: (4, 1)
-    #   # ┌──────┐
-    #   # │ foo  │
-    #   # │ ---  │
-    #   # │ f64  │
-    #   # ╞══════╡
-    #   # │ 1.0  │
-    #   # │ 8.0  │
-    #   # │ 27.0 │
-    #   # │ 64.0 │
-    #   # └──────┘
+    #   # shape: (4, 3)
+    #   # ┌─────┬──────┬────────────┐
+    #   # │ x   ┆ cube ┆ x ** xlog2 │
+    #   # │ --- ┆ ---  ┆ ---        │
+    #   # │ i64 ┆ i64  ┆ f64        │
+    #   # ╞═════╪══════╪════════════╡
+    #   # │ 1   ┆ 1    ┆ 1.0        │
+    #   # │ 2   ┆ 8    ┆ 2.0        │
+    #   # │ 4   ┆ 64   ┆ 16.0       │
+    #   # │ 8   ┆ 512  ┆ 512.0      │
+    #   # └─────┴──────┴────────────┘
     def pow(exponent)
       self**exponent
     end
@@ -5711,13 +5712,13 @@ def entropy(base: 2, normalize: true)
     #   # ┌────────┐
     #   # │ values │
     #   # │ ---    │
-    #   # │ f64    │
+    #   # │ i64    │
     #   # ╞════════╡
-    #   # │ 0.0    │
-    #   # │ -3.0   │
-    #   # │ -8.0   │
-    #   # │ -15.0  │
-    #   # │ -24.0  │
+    #   # │ 0      │
+    #   # │ -3     │
+    #   # │ -8     │
+    #   # │ -15    │
+    #   # │ -24    │
     #   # └────────┘
     def cumulative_eval(expr, min_periods: 1, parallel: false)
       _from_rbexpr(
diff --git a/lib/polars/functions/lazy.rb b/lib/polars/functions/lazy.rb
index 14d7325d75..f5a6bf4477 100644
--- a/lib/polars/functions/lazy.rb
+++ b/lib/polars/functions/lazy.rb
@@ -1264,10 +1264,10 @@ def from_epoch(column, unit: "s", eager: false)
     #   # ┌─────┬─────┬───────┐
     #   # │ a   ┆ a_a ┆ a_txt │
     #   # │ --- ┆ --- ┆ ---   │
-    #   # │ i64 ┆ f64 ┆ str   │
+    #   # │ i64 ┆ i64 ┆ str   │
     #   # ╞═════╪═════╪═══════╡
-    #   # │ 2   ┆ 4.0 ┆ 2     │
-    #   # │ 1   ┆ 1.0 ┆ 1     │
+    #   # │ 2   ┆ 4   ┆ 2     │
+    #   # │ 1   ┆ 1   ┆ 1     │
     #   # └─────┴─────┴───────┘
     def sql_expr(sql)
       if sql.is_a?(::String)
diff --git a/lib/polars/lazy_frame.rb b/lib/polars/lazy_frame.rb
index 678e0128d5..86c7936037 100644
--- a/lib/polars/lazy_frame.rb
+++ b/lib/polars/lazy_frame.rb
@@ -105,6 +105,7 @@ def self._scan_parquet(
       _from_rbldf(
         RbLazyFrame.new_from_parquet(
           file,
+          [],
           n_rows,
           cache,
           parallel,
@@ -112,7 +113,8 @@ def self._scan_parquet(
           Utils._prepare_row_count_args(row_count_name, row_count_offset),
           low_memory,
           use_statistics,
-          hive_partitioning
+          hive_partitioning,
+          nil
         )
       )
     end
@@ -402,16 +404,16 @@ def describe_optimized_plan(
     #   # │ 2   ┆ 7.0 ┆ b   │
     #   # │ 1   ┆ 6.0 ┆ a   │
     #   # └─────┴─────┴─────┘
-    def sort(by, reverse: false, nulls_last: false, maintain_order: false)
+    def sort(by, reverse: false, nulls_last: false, maintain_order: false, multithreaded: true)
       if by.is_a?(::String)
-        return _from_rbldf(_ldf.sort(by, reverse, nulls_last, maintain_order))
+        return _from_rbldf(_ldf.sort(by, reverse, nulls_last, maintain_order, multithreaded))
       end
       if Utils.bool?(reverse)
         reverse = [reverse]
       end
 
       by = Utils.selection_to_rbexpr_list(by)
-      _from_rbldf(_ldf.sort_by_exprs(by, reverse, nulls_last, maintain_order))
+      _from_rbldf(_ldf.sort_by_exprs(by, reverse, nulls_last, maintain_order, multithreaded))
     end
 
     # def profile
@@ -1525,12 +1527,13 @@ def rolling(
     #     closed: "right"
     #   ).agg(Polars.col("A").alias("A_agg_list"))
     #   # =>
-    #   # shape: (3, 4)
+    #   # shape: (4, 4)
     #   # ┌─────────────────┬─────────────────┬─────┬─────────────────┐
     #   # │ _lower_boundary ┆ _upper_boundary ┆ idx ┆ A_agg_list      │
     #   # │ ---             ┆ ---             ┆ --- ┆ ---             │
     #   # │ i64             ┆ i64             ┆ i64 ┆ list[str]       │
     #   # ╞═════════════════╪═════════════════╪═════╪═════════════════╡
+    #   # │ -2              ┆ 1               ┆ -2  ┆ ["A", "A"]      │
     #   # │ 0               ┆ 3               ┆ 0   ┆ ["A", "B", "B"] │
     #   # │ 2               ┆ 5               ┆ 2   ┆ ["B", "B", "C"] │
     #   # │ 4               ┆ 7               ┆ 4   ┆ ["C"]           │
@@ -1893,16 +1896,16 @@ def join(
     #   ).collect
     #   # =>
     #   # shape: (4, 6)
-    #   # ┌─────┬──────┬───────┬──────┬──────┬───────┐
-    #   # │ a   ┆ b    ┆ c     ┆ a^2  ┆ b/2  ┆ not c │
-    #   # │ --- ┆ ---  ┆ ---   ┆ ---  ┆ ---  ┆ ---   │
-    #   # │ i64 ┆ f64  ┆ bool  ┆ f64  ┆ f64  ┆ bool  │
-    #   # ╞═════╪══════╪═══════╪══════╪══════╪═══════╡
-    #   # │ 1   ┆ 0.5  ┆ true  ┆ 1.0  ┆ 0.25 ┆ false │
-    #   # │ 2   ┆ 4.0  ┆ true  ┆ 4.0  ┆ 2.0  ┆ false │
-    #   # │ 3   ┆ 10.0 ┆ false ┆ 9.0  ┆ 5.0  ┆ true  │
-    #   # │ 4   ┆ 13.0 ┆ true  ┆ 16.0 ┆ 6.5  ┆ false │
-    #   # └─────┴──────┴───────┴──────┴──────┴───────┘
+    #   # ┌─────┬──────┬───────┬─────┬──────┬───────┐
+    #   # │ a   ┆ b    ┆ c     ┆ a^2 ┆ b/2  ┆ not c │
+    #   # │ --- ┆ ---  ┆ ---   ┆ --- ┆ ---  ┆ ---   │
+    #   # │ i64 ┆ f64  ┆ bool  ┆ i64 ┆ f64  ┆ bool  │
+    #   # ╞═════╪══════╪═══════╪═════╪══════╪═══════╡
+    #   # │ 1   ┆ 0.5  ┆ true  ┆ 1   ┆ 0.25 ┆ false │
+    #   # │ 2   ┆ 4.0  ┆ true  ┆ 4   ┆ 2.0  ┆ false │
+    #   # │ 3   ┆ 10.0 ┆ false ┆ 9   ┆ 5.0  ┆ true  │
+    #   # │ 4   ┆ 13.0 ┆ true  ┆ 16  ┆ 6.5  ┆ false │
+    #   # └─────┴──────┴───────┴─────┴──────┴───────┘
     def with_columns(*exprs, **named_exprs)
       structify = ENV.fetch("POLARS_AUTO_STRUCTIFY", "0") != "0"
       rbexprs = Utils.parse_as_list_of_expressions(*exprs, **named_exprs, __structify: structify)
@@ -1967,26 +1970,26 @@ def with_context(other)
     #   # ┌─────┬─────┬───────────┐
     #   # │ a   ┆ b   ┆ b_squared │
     #   # │ --- ┆ --- ┆ ---       │
-    #   # │ i64 ┆ i64 ┆ f64       │
+    #   # │ i64 ┆ i64 ┆ i64       │
     #   # ╞═════╪═════╪═══════════╡
-    #   # │ 1   ┆ 2   ┆ 4.0       │
-    #   # │ 3   ┆ 4   ┆ 16.0      │
-    #   # │ 5   ┆ 6   ┆ 36.0      │
+    #   # │ 1   ┆ 2   ┆ 4         │
+    #   # │ 3   ┆ 4   ┆ 16        │
+    #   # │ 5   ┆ 6   ┆ 36        │
     #   # └─────┴─────┴───────────┘
     #
     # @example
     #   df.with_column(Polars.col("a") ** 2).collect
     #   # =>
     #   # shape: (3, 2)
-    #   # ┌──────┬─────┐
-    #   # │ a    ┆ b   │
-    #   # │ ---  ┆ --- │
-    #   # │ f64  ┆ i64 │
-    #   # ╞══════╪═════╡
-    #   # │ 1.0  ┆ 2   │
-    #   # │ 9.0  ┆ 4   │
-    #   # │ 25.0 ┆ 6   │
-    #   # └──────┴─────┘
+    #   # ┌─────┬─────┐
+    #   # │ a   ┆ b   │
+    #   # │ --- ┆ --- │
+    #   # │ i64 ┆ i64 │
+    #   # ╞═════╪═════╡
+    #   # │ 1   ┆ 2   │
+    #   # │ 9   ┆ 4   │
+    #   # │ 25  ┆ 6   │
+    #   # └─────┴─────┘
     def with_column(column)
       with_columns([column])
     end
diff --git a/lib/polars/list_expr.rb b/lib/polars/list_expr.rb
index c9501f8870..80924459e9 100644
--- a/lib/polars/list_expr.rb
+++ b/lib/polars/list_expr.rb
@@ -365,6 +365,10 @@ def concat(other)
     #
     # @param index [Integer]
     #   Index to return per sublist
+    # @param null_on_oob [Boolean]
+    #   Behavior if an index is out of bounds:
+    #   true -> set as null
+    #   false -> raise an error
     #
     # @return [Expr]
     #
@@ -382,9 +386,9 @@ def concat(other)
     #   # │ null │
     #   # │ 1    │
     #   # └──────┘
-    def get(index)
+    def get(index, null_on_oob: true)
       index = Utils.parse_as_expression(index)
-      Utils.wrap_expr(_rbexpr.list_get(index))
+      Utils.wrap_expr(_rbexpr.list_get(index, null_on_oob))
     end
 
     # Get the value by index in the sublists.
diff --git a/lib/polars/series.rb b/lib/polars/series.rb
index 8e74f59603..114ab2cce7 100644
--- a/lib/polars/series.rb
+++ b/lib/polars/series.rb
@@ -1155,13 +1155,13 @@ def entropy(base: Math::E, normalize: false)
     #   s.cumulative_eval(Polars.element.first - Polars.element.last ** 2)
     #   # =>
     #   # shape: (5,)
-    #   # Series: 'values' [f64]
+    #   # Series: 'values' [i64]
     #   # [
-    #   #         0.0
-    #   #         -3.0
-    #   #         -8.0
-    #   #         -15.0
-    #   #         -24.0
+    #   #         0
+    #   #         -3
+    #   #         -8
+    #   #         -15
+    #   #         -24
     #   # ]
     def cumulative_eval(expr, min_periods: 1, parallel: false)
       super
@@ -1567,12 +1567,12 @@ def take_every(n)
     #   #         2
     #   #         1
     #   # ]
-    def sort(reverse: false, nulls_last: false, in_place: false)
+    def sort(reverse: false, nulls_last: false, multithreaded: true, in_place: false)
       if in_place
-        self._s = _s.sort(reverse, nulls_last)
+        self._s = _s.sort(reverse, nulls_last, multithreaded)
         self
       else
-        Utils.wrap_s(_s.sort(reverse, nulls_last))
+        Utils.wrap_s(_s.sort(reverse, nulls_last, multithreaded))
       end
     end
 
diff --git a/lib/polars/string_expr.rb b/lib/polars/string_expr.rb
index ed9f0e213a..709a1cc355 100644
--- a/lib/polars/string_expr.rb
+++ b/lib/polars/string_expr.rb
@@ -1354,6 +1354,7 @@ def explode
     #   # │ null ┆ null   │
     #   # └──────┴────────┘
     def to_integer(base: 10, strict: true)
+      base = Utils.parse_as_expression(base, str_as_lit: false)
       Utils.wrap_expr(_rbexpr.str_to_integer(base, strict))
     end
 
diff --git a/test/lazy_frame_test.rb b/test/lazy_frame_test.rb
index ba329182fa..e68a6592e9 100644
--- a/test/lazy_frame_test.rb
+++ b/test/lazy_frame_test.rb
@@ -68,7 +68,7 @@ def test_pearson_corr
 
   def test_describe_optimized_plan
     df = Polars::DataFrame.new({"a" => [1, 2, 3]}).lazy
-    assert_match "FAST_PROJECT", df.select("a").describe_optimized_plan
+    assert_match "PROJECT", df.select("a").describe_optimized_plan
   end
 
   def test_concat