diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index ba231b07..9e1cdeda 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "1.21.0"
+  ".": "1.21.1"
 }
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2db87fef..1c10e20f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,14 @@
 # Changelog
 
+## 1.21.1 (2025-04-11)
+
+Full Changelog: [v1.21.0...v1.21.1](https://github.com/Finch-API/finch-api-python/compare/v1.21.0...v1.21.1)
+
+### Bug Fixes
+
+* **perf:** optimize some hot paths ([4fe846e](https://github.com/Finch-API/finch-api-python/commit/4fe846ea14d90fb142eb1d2b3d7fa259326604f8))
+* **perf:** skip traversing types for NotGiven values ([c6df147](https://github.com/Finch-API/finch-api-python/commit/c6df1471d194dcad32a5ab771f8a7fe19e904f9f))
+
 ## 1.21.0 (2025-04-09)
 
 Full Changelog: [v1.20.1...v1.21.0](https://github.com/Finch-API/finch-api-python/compare/v1.20.1...v1.21.0)
diff --git a/pyproject.toml b/pyproject.toml
index 0080f7bf..241689ff 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "finch-api"
-version = "1.21.0"
+version = "1.21.1"
 description = "The official Python library for the Finch API"
 dynamic = ["readme"]
 license = "Apache-2.0"
diff --git a/src/finch/_utils/_transform.py b/src/finch/_utils/_transform.py
index 3ec62081..b0cc20a7 100644
--- a/src/finch/_utils/_transform.py
+++ b/src/finch/_utils/_transform.py
@@ -5,13 +5,15 @@
 import pathlib
 from typing import Any, Mapping, TypeVar, cast
 from datetime import date, datetime
-from typing_extensions import Literal, get_args, override, get_type_hints
+from typing_extensions import Literal, get_args, override, get_type_hints as _get_type_hints
 
 import anyio
 import pydantic
 
 from ._utils import (
     is_list,
+    is_given,
+    lru_cache,
     is_mapping,
     is_iterable,
 )
@@ -108,6 +110,7 @@ class Params(TypedDict, total=False):
     return cast(_T, transformed)
 
 
+@lru_cache(maxsize=8096)
 def _get_annotated_type(type_: type) -> type | None:
     """If the given type is an `Annotated` type then it is returned, if not `None` is returned.
 
@@ -258,6 +261,11 @@ def _transform_typeddict(
     result: dict[str, object] = {}
     annotations = get_type_hints(expected_type, include_extras=True)
     for key, value in data.items():
+        if not is_given(value):
+            # we don't need to include `NotGiven` values here as they'll
+            # be stripped out before the request is sent anyway
+            continue
+
         type_ = annotations.get(key)
         if type_ is None:
             # we do not have a type annotation for this field, leave it as is
@@ -415,6 +423,11 @@ async def _async_transform_typeddict(
     result: dict[str, object] = {}
     annotations = get_type_hints(expected_type, include_extras=True)
     for key, value in data.items():
+        if not is_given(value):
+            # we don't need to include `NotGiven` values here as they'll
+            # be stripped out before the request is sent anyway
+            continue
+
         type_ = annotations.get(key)
         if type_ is None:
             # we do not have a type annotation for this field, leave it as is
@@ -422,3 +435,13 @@ async def _async_transform_typeddict(
         else:
             result[_maybe_transform_key(key, type_)] = await _async_transform_recursive(value, annotation=type_)
     return result
+
+
+@lru_cache(maxsize=8096)
+def get_type_hints(
+    obj: Any,
+    globalns: dict[str, Any] | None = None,
+    localns: Mapping[str, Any] | None = None,
+    include_extras: bool = False,
+) -> dict[str, Any]:
+    return _get_type_hints(obj, globalns=globalns, localns=localns, include_extras=include_extras)
diff --git a/src/finch/_utils/_typing.py b/src/finch/_utils/_typing.py
index 278749b1..1958820f 100644
--- a/src/finch/_utils/_typing.py
+++ b/src/finch/_utils/_typing.py
@@ -13,6 +13,7 @@
     get_origin,
 )
 
+from ._utils import lru_cache
 from .._types import InheritsGeneric
 from .._compat import is_union as _is_union
 
@@ -66,6 +67,7 @@ def is_type_alias_type(tp: Any, /) -> TypeIs[typing_extensions.TypeAliasType]:
 
 
 # Extracts T from Annotated[T, ...] or from Required[Annotated[T, ...]]
+@lru_cache(maxsize=8096)
 def strip_annotated_type(typ: type) -> type:
     if is_required_type(typ) or is_annotated_type(typ):
         return strip_annotated_type(cast(type, get_args(typ)[0]))
diff --git a/src/finch/_version.py b/src/finch/_version.py
index 4bdbe1a5..525c4d96 100644
--- a/src/finch/_version.py
+++ b/src/finch/_version.py
@@ -1,4 +1,4 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
 
 __title__ = "finch"
-__version__ = "1.21.0"  # x-release-please-version
+__version__ = "1.21.1"  # x-release-please-version
diff --git a/tests/test_transform.py b/tests/test_transform.py
index 80271b12..6ea64018 100644
--- a/tests/test_transform.py
+++ b/tests/test_transform.py
@@ -8,7 +8,7 @@
 
 import pytest
 
-from finch._types import Base64FileInput
+from finch._types import NOT_GIVEN, Base64FileInput
 from finch._utils import (
     PropertyInfo,
     transform as _transform,
@@ -444,3 +444,10 @@ async def test_transform_skipping(use_async: bool) -> None:
     # iterables of ints are converted to a list
     data = iter([1, 2, 3])
     assert await transform(data, Iterable[int], use_async) == [1, 2, 3]
+
+
+@parametrize
+@pytest.mark.asyncio
+async def test_strips_notgiven(use_async: bool) -> None:
+    assert await transform({"foo_bar": "bar"}, Foo1, use_async) == {"fooBar": "bar"}
+    assert await transform({"foo_bar": NOT_GIVEN}, Foo1, use_async) == {}