diff --git a/lib/explorer/backend/data_frame.ex b/lib/explorer/backend/data_frame.ex
index 5dd78c83d..f6fb8c249 100644
--- a/lib/explorer/backend/data_frame.ex
+++ b/lib/explorer/backend/data_frame.ex
@@ -168,7 +168,7 @@ defmodule Explorer.Backend.DataFrame do
   @callback lazy(df) :: df
   @callback collect(df) :: df
   @callback from_tabular(Table.Reader.t(), io_dtypes) :: df
-  @callback from_series([{binary(), Series.t()}]) :: df
+  @callback from_series([{binary(), series()}]) :: df
   @callback to_rows(df, atom_keys? :: boolean()) :: [map()]
   @callback to_rows_stream(df, atom_keys? :: boolean(), chunk_size :: integer()) :: Enumerable.t()
 
diff --git a/lib/explorer/backend/lazy_series.ex b/lib/explorer/backend/lazy_series.ex
index 26ee1080f..607abb030 100644
--- a/lib/explorer/backend/lazy_series.ex
+++ b/lib/explorer/backend/lazy_series.ex
@@ -822,7 +822,6 @@ defmodule Explorer.Backend.LazySeries do
        when op in [:first, :last, :sum, :min, :max, :product],
        do: series.dtype
 
-  defp dtype_for_agg_operation(op, _) when op in [:all?, :any?], do: :boolean
   defp dtype_for_agg_operation(:mode, series), do: {:list, series.dtype}
 
   defp dtype_for_agg_operation(_, _), do: {:f, 64}
@@ -1077,13 +1076,6 @@ defmodule Explorer.Backend.LazySeries do
 
   defp to_elixir_ast(other), do: other
 
-  @impl true
-  def size(series) do
-    data = new(:size, [lazy_series!(series)], {:u, 32})
-
-    Backend.Series.new(data, {:u, 32})
-  end
-
   @impl true
   def transform(_series, _fun) do
     raise """
diff --git a/lib/explorer/polars_backend/expression.ex b/lib/explorer/polars_backend/expression.ex
index 93092fe63..3abc34c2b 100644
--- a/lib/explorer/polars_backend/expression.ex
+++ b/lib/explorer/polars_backend/expression.ex
@@ -322,7 +322,10 @@ defmodule Explorer.PolarsBackend.Expression do
     Native.expr_int_range(to_expr(0), size_expr, 1, {:u, 32})
   end
 
-  for {op, arity} <- @all_expressions do
+  for {op, arity} when op not in [
+    :acos, :asin, :atan, :cos, :degrees, :radians, :sin, :tan,
+    :variance, :exp, :skew, :standard_deviation
+  ] <- @all_expressions do
     args = Macro.generate_arguments(arity, __MODULE__)
 
     updates =
diff --git a/lib/explorer/series.ex b/lib/explorer/series.ex
index 3b979d4ed..1f22aa6d8 100644
--- a/lib/explorer/series.ex
+++ b/lib/explorer/series.ex
@@ -1143,7 +1143,7 @@ defmodule Explorer.Series do
     do: apply_series(series, :strftime, [format_string])
 
   def strftime(%Series{dtype: dtype}, _format_string),
-    do: dtype_error("strftime/2", dtype, :datetime_like)
+    do: dtype_error("strftime/2", dtype, [:datetime_like])
 
   @doc """
   Clip (or clamp) the values in a series.
@@ -3483,9 +3483,6 @@ defmodule Explorer.Series do
   defp maybe_max(left, right) when K.and(is_integer(left), is_integer(right)),
     do: K.max(left, right)
 
-  defp maybe_max(left, nil), do: left
-  defp maybe_max(nil, right), do: right
-
   @doc """
   Subtracts right from left, element-wise.
 
@@ -5346,15 +5343,15 @@ defmodule Explorer.Series do
 
     float_series =
       case dtype(series) do
-        :f32 ->
+        {:f, 32} ->
           series
 
-        :f64 ->
+        {:f, 64} ->
           series
 
         _ ->
           try do
-            cast(series, :f64)
+            cast(series, {:f, 64})
           rescue
             _ ->
               raise ArgumentError,
diff --git a/mix.exs b/mix.exs
index 5dec87917..1946c0d32 100644
--- a/mix.exs
+++ b/mix.exs
@@ -18,7 +18,7 @@ defmodule Explorer.MixProject do
       package: package(),
       deps: deps(),
       docs: docs(),
-      preferred_cli_env: [ci: :test, "localstack.setup": :test],
+      cli: cli(),
       aliases: [
         "rust.lint": ["cmd cargo clippy --manifest-path=native/explorer/Cargo.toml -- -Dwarnings"],
         "rust.fmt": ["cmd cargo fmt --manifest-path=native/explorer/Cargo.toml --all"],
@@ -35,6 +35,10 @@ defmodule Explorer.MixProject do
     ]
   end
 
+  def cli do
+    [preferred_envs: [ci: :test, "localstack.setup": :test]]
+  end
+
   defp elixirc_paths(:test), do: ~w(lib test/support)
   defp elixirc_paths(_), do: ~w(lib)