diff --git a/packages/aws-event-stream/pyproject.toml b/packages/aws-event-stream/pyproject.toml
index 82c4cf1cf..eb7f20268 100644
--- a/packages/aws-event-stream/pyproject.toml
+++ b/packages/aws-event-stream/pyproject.toml
@@ -17,3 +17,6 @@ build-backend = "hatchling.build"
 exclude = [
   "tests",
 ]
+
+[tool.ruff]
+src = ["src"]
diff --git a/packages/aws-event-stream/src/aws_event_stream/events.py b/packages/aws-event-stream/src/aws_event_stream/events.py
index cdd76d493..8d52bde65 100644
--- a/packages/aws-event-stream/src/aws_event_stream/events.py
+++ b/packages/aws-event-stream/src/aws_event_stream/events.py
@@ -15,6 +15,7 @@
 from dataclasses import dataclass
 from io import BytesIO
 from struct import pack, unpack
+from types import MappingProxyType
 from typing import Literal, Self
 
 from smithy_core.aio.interfaces import AsyncByteStream
@@ -610,11 +611,13 @@ class _DecodeUtils:
     INT64_BYTE_FORMAT = "!q"
 
     # uint byte size to unpack format
-    UINT_BYTE_FORMAT: dict[_ArraySize, str] = {
-        1: UINT8_BYTE_FORMAT,
-        2: UINT16_BYTE_FORMAT,
-        4: UINT32_BYTE_FORMAT,
-    }
+    UINT_BYTE_FORMAT: Mapping[_ArraySize, str] = MappingProxyType(
+        {
+            1: UINT8_BYTE_FORMAT,
+            2: UINT16_BYTE_FORMAT,
+            4: UINT32_BYTE_FORMAT,
+        }
+    )
 
     @staticmethod
     def unpack_uint8(data: BytesLike) -> tuple[int, int]:
@@ -749,20 +752,24 @@ class EventHeaderDecoder(Iterator[tuple[str, HEADER_VALUE]]):
 
     # Maps header type to appropriate unpacking function
     # These unpacking functions return the value and the amount unpacked
-    _HEADER_TYPE_MAP: dict[int, Callable[[BytesLike], tuple[HEADER_VALUE, int]]] = {
-        # Boolean headers have no data bytes following the type signifier, so they
-        # can just return static values.
-        0: lambda b: (True, 0),  # boolean_true
-        1: lambda b: (False, 0),  # boolean_false
-        2: _DecodeUtils.unpack_int8,  # byte
-        3: _DecodeUtils.unpack_int16,  # short
-        4: _DecodeUtils.unpack_int32,  # integer
-        5: _DecodeUtils.unpack_int64,  # long
-        6: _DecodeUtils.unpack_byte_array,  # byte_array
-        7: _DecodeUtils.unpack_utf8_string,  # string
-        8: _DecodeUtils.unpack_timestamp,  # timestamp
-        9: _DecodeUtils.unpack_uuid,  # uuid
-    }
+    _HEADER_TYPE_MAP: Mapping[int, Callable[[BytesLike], tuple[HEADER_VALUE, int]]] = (
+        MappingProxyType(
+            {
+                # Boolean headers have no data bytes following the type signifier, so they
+                # can just return static values.
+                0: lambda b: (True, 0),  # boolean_true
+                1: lambda b: (False, 0),  # boolean_false
+                2: _DecodeUtils.unpack_int8,  # byte
+                3: _DecodeUtils.unpack_int16,  # short
+                4: _DecodeUtils.unpack_int32,  # integer
+                5: _DecodeUtils.unpack_int64,  # long
+                6: _DecodeUtils.unpack_byte_array,  # byte_array
+                7: _DecodeUtils.unpack_utf8_string,  # string
+                8: _DecodeUtils.unpack_timestamp,  # timestamp
+                9: _DecodeUtils.unpack_uuid,  # uuid
+            }
+        )
+    )
 
     def __init__(self, header_bytes: BytesLike) -> None:
         """Initialize an event header decoder.
diff --git a/packages/smithy-aws-core/pyproject.toml b/packages/smithy-aws-core/pyproject.toml
index 1d628f474..991c6130b 100644
--- a/packages/smithy-aws-core/pyproject.toml
+++ b/packages/smithy-aws-core/pyproject.toml
@@ -16,3 +16,6 @@ build-backend = "hatchling.build"
 exclude = [
   "tests",
 ]
+
+[tool.ruff]
+src = ["src"]
diff --git a/packages/smithy-core/pyproject.toml b/packages/smithy-core/pyproject.toml
index 91d867d73..81856563c 100644
--- a/packages/smithy-core/pyproject.toml
+++ b/packages/smithy-core/pyproject.toml
@@ -19,3 +19,6 @@ build-backend = "hatchling.build"
 exclude = [
   "tests",
 ]
+
+[tool.ruff]
+src = ["src"]
diff --git a/packages/smithy-core/src/smithy_core/documents.py b/packages/smithy-core/src/smithy_core/documents.py
index 89328a7a7..4f01d6916 100644
--- a/packages/smithy-core/src/smithy_core/documents.py
+++ b/packages/smithy-core/src/smithy_core/documents.py
@@ -230,7 +230,7 @@ def _wrap_map(self, value: Mapping[str, DocumentValue]) -> dict[str, "Document"]
                 member_schema = self._schema.members["value"]
             return {k: self._new_document(v, member_schema) for k, v in value.items()}
 
-        result: dict[str, "Document"] = {}
+        result: dict[str, Document] = {}
         for k, v in value.items():
             result[k] = self._new_document(v, self._schema.members[k])
         return result
diff --git a/packages/smithy-core/src/smithy_core/identity.py b/packages/smithy-core/src/smithy_core/identity.py
index bc8c49929..ed570bffd 100644
--- a/packages/smithy-core/src/smithy_core/identity.py
+++ b/packages/smithy-core/src/smithy_core/identity.py
@@ -1,6 +1,6 @@
 #  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 #  SPDX-License-Identifier: Apache-2.0
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 
 from .interfaces import identity as identity_interface
 from .utils import ensure_utc
@@ -28,4 +28,4 @@ def is_expired(self) -> bool:
         """Whether the identity is expired."""
         if self.expiration is None:
             return False
-        return datetime.now(tz=timezone.utc) >= self.expiration
+        return datetime.now(tz=UTC) >= self.expiration
diff --git a/packages/smithy-core/src/smithy_core/interceptors.py b/packages/smithy-core/src/smithy_core/interceptors.py
index 0b64d4e90..7b358736d 100644
--- a/packages/smithy-core/src/smithy_core/interceptors.py
+++ b/packages/smithy-core/src/smithy_core/interceptors.py
@@ -148,7 +148,6 @@ def read_before_execution(
         the `response`. If multiple `read_before_execution` methods throw exceptions,
         the latest will be used and earlier ones will be logged and dropped.
         """
-        pass
 
     def modify_before_serialization(
         self, context: InterceptorContext[Request, None, None, None]
@@ -193,7 +192,6 @@ def read_before_serialization(
         If exceptions are thrown by this hook, execution will jump to
         `modify_before_completion` with the thrown exception as the `response`.
         """
-        pass
 
     def read_after_serialization(
         self, context: InterceptorContext[Request, None, TransportRequest, None]
@@ -214,7 +212,6 @@ def read_after_serialization(
         If exceptions are thrown by this hook, execution will jump to
         `modify_before_completion` with the thrown exception as the `response`.
         """
-        pass
 
     def modify_before_retry_loop(
         self, context: InterceptorContext[Request, None, TransportRequest, None]
@@ -259,7 +256,6 @@ def read_before_attempt(
         exception as the `response` If multiple `read_before_attempt` methods throw
         exceptions, the latest will be used and earlier ones will be logged and dropped.
         """
-        pass
 
     def modify_before_signing(
         self, context: InterceptorContext[Request, None, TransportRequest, None]
@@ -309,7 +305,6 @@ def read_before_signing(
         If exceptions are thrown by this hook, execution will jump to
         `modify_before_attempt_completion` with the thrown exception as the `response`.
         """
-        pass
 
     def read_after_signing(
         self, context: InterceptorContext[Request, None, TransportRequest, None]
@@ -333,7 +328,6 @@ def read_after_signing(
         If exceptions are thrown by this hook, execution will jump to
         `modify_before_attempt_completion` with the thrown exception as the `response`.
         """
-        pass
 
     def modify_before_transmit(
         self, context: InterceptorContext[Request, None, TransportRequest, None]
@@ -384,7 +378,6 @@ def read_before_transmit(
         If exceptions are thrown by this hook, execution will jump to
         `modify_before_attempt_completion` with the thrown exception as the `response`.
         """
-        pass
 
     def read_after_transmit(
         self,
@@ -411,7 +404,6 @@ def read_after_transmit(
         If exceptions are thrown by this hook, execution will jump to
         `modify_before_attempt_completion` with the thrown exception as the `response`.
         """
-        pass
 
     def modify_before_deserialization(
         self,
@@ -467,7 +459,6 @@ def read_before_deserialization(
         If exceptions are thrown by this hook, execution will jump to
         `modify_before_attempt_completion` with the thrown exception as the `response`.
         """
-        pass
 
     def read_after_deserialization(
         self,
@@ -495,7 +486,6 @@ def read_after_deserialization(
         If exceptions are thrown by this hook, execution will jump to
         `modify_before_attempt_completion` with the thrown exception as the `response`.
         """
-        pass
 
     def modify_before_attempt_completion(
         self,
@@ -554,7 +544,6 @@ def read_after_attempt(
         execution will then jump to `read_before_attempt`. Otherwise, execution will
         jump to `modify_before_completion` with the thrown exception as the `response`.
         """
-        pass
 
     def modify_before_completion(
         self,
@@ -605,4 +594,3 @@ def read_after_execution(
         final response. If multiple `read_after_execution` methods throw exceptions,
         the latest will be used and earlier ones will be logged and dropped.
         """
-        pass
diff --git a/packages/smithy-core/src/smithy_core/interfaces/identity.py b/packages/smithy-core/src/smithy_core/interfaces/identity.py
index 095314637..765e32c22 100644
--- a/packages/smithy-core/src/smithy_core/interfaces/identity.py
+++ b/packages/smithy-core/src/smithy_core/interfaces/identity.py
@@ -25,8 +25,6 @@ def is_expired(self) -> bool:
 class IdentityProperties(TypedDict):
     """Properties used to help determine the identity to return."""
 
-    ...
-
 
 IdentityPropertiesType = TypeVar("IdentityPropertiesType", bound=IdentityProperties)
 IdentityPropertiesType_contra = TypeVar(
diff --git a/packages/smithy-core/src/smithy_core/retries.py b/packages/smithy-core/src/smithy_core/retries.py
index e9c75913f..07b051da9 100644
--- a/packages/smithy-core/src/smithy_core/retries.py
+++ b/packages/smithy-core/src/smithy_core/retries.py
@@ -242,4 +242,3 @@ def refresh_retry_token_for_retry(
 
     def record_success(self, *, token: retries_interface.RetryToken) -> None:
         """Not used by this retry strategy."""
-        pass
diff --git a/packages/smithy-core/src/smithy_core/schemas.py b/packages/smithy-core/src/smithy_core/schemas.py
index 0e725d129..967eb7a78 100644
--- a/packages/smithy-core/src/smithy_core/schemas.py
+++ b/packages/smithy-core/src/smithy_core/schemas.py
@@ -50,8 +50,8 @@ def __init__(
         if any(_member_props) and not all(_member_props):
             raise SmithyException(
                 "If any member property is set, all member properties must be set. "
-                f"member_name: {repr(id.member)}, member_target: "
-                f"{repr(member_target)}, member_index: {repr(member_index)}"
+                f"member_name: {id.member!r}, member_target: "
+                f"{member_target!r}, member_index: {member_index!r}"
             )
 
         # setattr is required because the class is frozen
@@ -67,7 +67,7 @@ def __init__(
 
         if members:
             if isinstance(members, list):
-                m: dict[str, "Schema"] = {}
+                m: dict[str, Schema] = {}
                 for member in members:
                     m[member.expect_member_name()] = member
                 members = m
@@ -140,7 +140,7 @@ def collection(
             constructor, this is a dict of member names to a simplified dict containing
             only ``traits`` and a ``target``. Member schemas will be generated from this.
         """
-        struct_members: dict[str, "Schema"] = {}
+        struct_members: dict[str, Schema] = {}
         if members:
             for k in members.keys():
                 struct_members[k] = cls.member(
diff --git a/packages/smithy-core/src/smithy_core/types.py b/packages/smithy-core/src/smithy_core/types.py
index fcc0921ef..f59327754 100644
--- a/packages/smithy-core/src/smithy_core/types.py
+++ b/packages/smithy-core/src/smithy_core/types.py
@@ -5,7 +5,7 @@
 from datetime import datetime
 from email.utils import format_datetime, parsedate_to_datetime
 from enum import Enum
-from typing import Any, TypeAlias
+from typing import Any
 
 from .exceptions import ExpectationNotMetException
 from .utils import (
@@ -16,7 +16,7 @@
     serialize_rfc3339,
 )
 
-Document: TypeAlias = (
+type Document = (
     Mapping[str, "Document"] | Sequence["Document"] | str | int | float | bool | None
 )
 
diff --git a/packages/smithy-core/src/smithy_core/utils.py b/packages/smithy-core/src/smithy_core/utils.py
index 375b68273..f063ad1aa 100644
--- a/packages/smithy-core/src/smithy_core/utils.py
+++ b/packages/smithy-core/src/smithy_core/utils.py
@@ -1,7 +1,7 @@
 #  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 #  SPDX-License-Identifier: Apache-2.0
 import re
-from datetime import datetime, timedelta, timezone
+from datetime import UTC, datetime, timedelta
 from decimal import Decimal
 from math import isinf, isnan
 from types import UnionType
@@ -24,9 +24,9 @@ def ensure_utc(value: datetime) -> datetime:
     :returns: A UTC timezone-aware equivalent datetime.
     """
     if value.tzinfo is None:
-        return value.replace(tzinfo=timezone.utc)
+        return value.replace(tzinfo=UTC)
     else:
-        return value.astimezone(timezone.utc)
+        return value.astimezone(UTC)
 
 
 # Python is way more permissive on value of non-numerical floats than Smithy is, so we
@@ -61,9 +61,9 @@ def epoch_seconds_to_datetime(value: int | float) -> datetime:
     to years from 1970 through 2038." This affects 32-bit systems.
     """
     try:
-        return datetime.fromtimestamp(value, tz=timezone.utc)
+        return datetime.fromtimestamp(value, tz=UTC)
     except OverflowError:
-        epoch_zero = datetime(1970, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
+        epoch_zero = datetime(1970, 1, 1, 0, 0, 0, tzinfo=UTC)
         return epoch_zero + timedelta(seconds=value)
 
 
diff --git a/packages/smithy-core/tests/unit/test_identity.py b/packages/smithy-core/tests/unit/test_identity.py
index dc0698ecd..350f26d5f 100644
--- a/packages/smithy-core/tests/unit/test_identity.py
+++ b/packages/smithy-core/tests/unit/test_identity.py
@@ -1,6 +1,6 @@
 #  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 #  SPDX-License-Identifier: Apache-2.0
-from datetime import datetime, timedelta, timezone
+from datetime import UTC, datetime, timedelta, timezone
 
 import pytest
 from freezegun import freeze_time
@@ -14,7 +14,7 @@
         None,
         timezone(timedelta(hours=3)),
         timezone(timedelta(hours=-3)),
-        timezone.utc,
+        UTC,
         timezone(timedelta(hours=0)),
         timezone(timedelta(hours=0, minutes=30)),
         timezone(timedelta(hours=0, minutes=-30)),
@@ -24,7 +24,7 @@ def test_expiration_timezone(time_zone: timezone) -> None:
     expiration = datetime.now(tz=time_zone)
     identity = Identity(expiration=expiration)
     assert identity.expiration is not None
-    assert identity.expiration.tzinfo == timezone.utc
+    assert identity.expiration.tzinfo == UTC
 
 
 @pytest.mark.parametrize(
@@ -32,20 +32,20 @@ def test_expiration_timezone(time_zone: timezone) -> None:
     [
         (
             Identity(
-                expiration=datetime(year=2023, month=1, day=1, tzinfo=timezone.utc),
+                expiration=datetime(year=2023, month=1, day=1, tzinfo=UTC),
             ),
             True,
         ),
         (Identity(), False),
         (
             Identity(
-                expiration=datetime(year=2023, month=1, day=2, tzinfo=timezone.utc),
+                expiration=datetime(year=2023, month=1, day=2, tzinfo=UTC),
             ),
             False,
         ),
         (
             Identity(
-                expiration=datetime(year=2022, month=12, day=31, tzinfo=timezone.utc),
+                expiration=datetime(year=2022, month=12, day=31, tzinfo=UTC),
             ),
             True,
         ),
diff --git a/packages/smithy-core/tests/unit/test_retries.py b/packages/smithy-core/tests/unit/test_retries.py
index 2d68da67a..e79173f66 100644
--- a/packages/smithy-core/tests/unit/test_retries.py
+++ b/packages/smithy-core/tests/unit/test_retries.py
@@ -53,8 +53,6 @@ def test_exponential_backoff_strategy(
 
     for delay_index, delay_expected in enumerate(expected_delays):
         delay_actual = bos.compute_next_backoff_delay(retry_attempt=delay_index)
-        delay_expected2 = delay_expected
-        print(f"{delay_index=} {delay_actual=} {delay_expected2=}")
         assert delay_actual == pytest.approx(delay_expected)  # type: ignore
 
 
diff --git a/packages/smithy-core/tests/unit/test_types.py b/packages/smithy-core/tests/unit/test_types.py
index a478aad31..b7c48b697 100644
--- a/packages/smithy-core/tests/unit/test_types.py
+++ b/packages/smithy-core/tests/unit/test_types.py
@@ -2,7 +2,7 @@
 #  SPDX-License-Identifier: Apache-2.0
 
 # pyright: reportPrivateUsage=false
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 
 import pytest
 
@@ -68,57 +68,57 @@ def test_blob_from_json_immediately_caches() -> None:
     (
         TimestampFormat.DATE_TIME,
         "2017-01-01T00:00:00Z",
-        datetime(2017, 1, 1, tzinfo=timezone.utc),
+        datetime(2017, 1, 1, tzinfo=UTC),
     ),
     (
         TimestampFormat.EPOCH_SECONDS,
         1483228800,
-        datetime(2017, 1, 1, tzinfo=timezone.utc),
+        datetime(2017, 1, 1, tzinfo=UTC),
     ),
     (
         TimestampFormat.HTTP_DATE,
         "Sun, 01 Jan 2017 00:00:00 GMT",
-        datetime(2017, 1, 1, tzinfo=timezone.utc),
+        datetime(2017, 1, 1, tzinfo=UTC),
     ),
     (
         TimestampFormat.DATE_TIME,
         "2017-01-01T00:00:00.000001Z",
-        datetime(2017, 1, 1, microsecond=1, tzinfo=timezone.utc),
+        datetime(2017, 1, 1, microsecond=1, tzinfo=UTC),
     ),
     (
         TimestampFormat.EPOCH_SECONDS,
         1483228800.000001,
-        datetime(2017, 1, 1, microsecond=1, tzinfo=timezone.utc),
+        datetime(2017, 1, 1, microsecond=1, tzinfo=UTC),
     ),
     (
         TimestampFormat.DATE_TIME,
         "1969-12-31T23:59:59Z",
-        datetime(1969, 12, 31, 23, 59, 59, tzinfo=timezone.utc),
+        datetime(1969, 12, 31, 23, 59, 59, tzinfo=UTC),
     ),
     (
         TimestampFormat.EPOCH_SECONDS,
         -1,
-        datetime(1969, 12, 31, 23, 59, 59, tzinfo=timezone.utc),
+        datetime(1969, 12, 31, 23, 59, 59, tzinfo=UTC),
     ),
     (
         TimestampFormat.HTTP_DATE,
         "Wed, 31 Dec 1969 23:59:59 GMT",
-        datetime(1969, 12, 31, 23, 59, 59, tzinfo=timezone.utc),
+        datetime(1969, 12, 31, 23, 59, 59, tzinfo=UTC),
     ),
     (
         TimestampFormat.DATE_TIME,
         "2038-01-19T03:14:08Z",
-        datetime(2038, 1, 19, 3, 14, 8, tzinfo=timezone.utc),
+        datetime(2038, 1, 19, 3, 14, 8, tzinfo=UTC),
     ),
     (
         TimestampFormat.EPOCH_SECONDS,
         2147483648,
-        datetime(2038, 1, 19, 3, 14, 8, tzinfo=timezone.utc),
+        datetime(2038, 1, 19, 3, 14, 8, tzinfo=UTC),
     ),
     (
         TimestampFormat.HTTP_DATE,
         "Tue, 19 Jan 2038 03:14:08 GMT",
-        datetime(2038, 1, 19, 3, 14, 8, tzinfo=timezone.utc),
+        datetime(2038, 1, 19, 3, 14, 8, tzinfo=UTC),
     ),
 ]
 
@@ -128,22 +128,22 @@ def test_blob_from_json_immediately_caches() -> None:
     (
         TimestampFormat.EPOCH_SECONDS,
         "1483228800",
-        datetime(2017, 1, 1, tzinfo=timezone.utc),
+        datetime(2017, 1, 1, tzinfo=UTC),
     ),
     (
         TimestampFormat.EPOCH_SECONDS,
         "1483228800.000001",
-        datetime(2017, 1, 1, microsecond=1, tzinfo=timezone.utc),
+        datetime(2017, 1, 1, microsecond=1, tzinfo=UTC),
     ),
     (
         TimestampFormat.EPOCH_SECONDS,
         "-1",
-        datetime(1969, 12, 31, 23, 59, 59, tzinfo=timezone.utc),
+        datetime(1969, 12, 31, 23, 59, 59, tzinfo=UTC),
     ),
     (
         TimestampFormat.EPOCH_SECONDS,
         "2147483648",
-        datetime(2038, 1, 19, 3, 14, 8, tzinfo=timezone.utc),
+        datetime(2038, 1, 19, 3, 14, 8, tzinfo=UTC),
     ),
 ]
 TIMESTAMP_FORMAT_DESERIALIZATION_CASES.extend(TIMESTAMP_FORMAT_SERIALIZATION_CASES)
diff --git a/packages/smithy-core/tests/unit/test_utils.py b/packages/smithy-core/tests/unit/test_utils.py
index 31d243d6b..dc1439a8e 100644
--- a/packages/smithy-core/tests/unit/test_utils.py
+++ b/packages/smithy-core/tests/unit/test_utils.py
@@ -4,7 +4,7 @@
 # mypy: allow-untyped-defs
 # mypy: allow-incomplete-defs
 
-from datetime import datetime, timedelta, timezone
+from datetime import UTC, datetime, timedelta, timezone
 from decimal import Decimal
 from math import isnan
 from typing import Any, NamedTuple
@@ -31,14 +31,14 @@
 @pytest.mark.parametrize(
     "given, expected",
     [
-        (datetime(2017, 1, 1), datetime(2017, 1, 1, tzinfo=timezone.utc)),
+        (datetime(2017, 1, 1), datetime(2017, 1, 1, tzinfo=UTC)),
         (
-            datetime(2017, 1, 1, tzinfo=timezone.utc),
-            datetime(2017, 1, 1, tzinfo=timezone.utc),
+            datetime(2017, 1, 1, tzinfo=UTC),
+            datetime(2017, 1, 1, tzinfo=UTC),
         ),
         (
             datetime(2017, 1, 1, tzinfo=timezone(timedelta(hours=1))),
-            datetime(2016, 12, 31, 23, tzinfo=timezone.utc),
+            datetime(2016, 12, 31, 23, tzinfo=UTC),
         ),
     ],
 )
@@ -200,19 +200,19 @@ class DateTimeTestcase(NamedTuple):
 
 DATETIME_TEST_CASES: list[DateTimeTestcase] = [
     DateTimeTestcase(
-        dt_object=datetime(2017, 1, 1, tzinfo=timezone.utc),
+        dt_object=datetime(2017, 1, 1, tzinfo=UTC),
         rfc3339_str="2017-01-01T00:00:00Z",
         epoch_seconds_num=1483228800,
         epoch_seconds_str="1483228800",
     ),
     DateTimeTestcase(
-        dt_object=datetime(2017, 1, 1, microsecond=1, tzinfo=timezone.utc),
+        dt_object=datetime(2017, 1, 1, microsecond=1, tzinfo=UTC),
         rfc3339_str="2017-01-01T00:00:00.000001Z",
         epoch_seconds_num=1483228800.000001,
         epoch_seconds_str="1483228800.000001",
     ),
     DateTimeTestcase(
-        dt_object=datetime(1969, 12, 31, 23, 59, 59, tzinfo=timezone.utc),
+        dt_object=datetime(1969, 12, 31, 23, 59, 59, tzinfo=UTC),
         rfc3339_str="1969-12-31T23:59:59Z",
         epoch_seconds_num=-1,
         epoch_seconds_str="-1",
@@ -220,7 +220,7 @@ class DateTimeTestcase(NamedTuple):
     # The first second affected by the Year 2038 problem where fromtimestamp raises an
     # OverflowError on 32-bit systems for dates beyond 2038-01-19 03:14:07 UTC.
     DateTimeTestcase(
-        dt_object=datetime(2038, 1, 19, 3, 14, 8, tzinfo=timezone.utc),
+        dt_object=datetime(2038, 1, 19, 3, 14, 8, tzinfo=UTC),
         rfc3339_str="2038-01-19T03:14:08Z",
         epoch_seconds_num=2147483648,
         epoch_seconds_str="2147483648",
@@ -270,7 +270,7 @@ def test_epoch_seconds_to_datetime_with_overflow_error(monkeypatch):  # type: ig
     datetime_mock = Mock(wraps=datetime)
     datetime_mock.fromtimestamp = Mock(side_effect=OverflowError())
     monkeypatch.setattr("smithy_core.utils.datetime", datetime_mock)  # type: ignore
-    dt_object = datetime(2038, 1, 19, 3, 14, 8, tzinfo=timezone.utc)
+    dt_object = datetime(2038, 1, 19, 3, 14, 8, tzinfo=UTC)
     assert epoch_seconds_to_datetime(2147483648) == dt_object
 
 
diff --git a/packages/smithy-event-stream/pyproject.toml b/packages/smithy-event-stream/pyproject.toml
index b4a0c5f6d..51406eceb 100644
--- a/packages/smithy-event-stream/pyproject.toml
+++ b/packages/smithy-event-stream/pyproject.toml
@@ -16,3 +16,6 @@ build-backend = "hatchling.build"
 exclude = [
   "tests",
 ]
+
+[tool.ruff]
+src = ["src"]
diff --git a/packages/smithy-http/pyproject.toml b/packages/smithy-http/pyproject.toml
index 26400ab3e..0693786e9 100644
--- a/packages/smithy-http/pyproject.toml
+++ b/packages/smithy-http/pyproject.toml
@@ -24,3 +24,6 @@ build-backend = "hatchling.build"
 exclude = [
   "tests",
 ]
+
+[tool.ruff]
+src = ["src"]
diff --git a/packages/smithy-http/src/smithy_http/__init__.py b/packages/smithy-http/src/smithy_http/__init__.py
index 90869db71..fb01c6d12 100644
--- a/packages/smithy-http/src/smithy_http/__init__.py
+++ b/packages/smithy-http/src/smithy_http/__init__.py
@@ -25,7 +25,7 @@ def __init__(
         kind: FieldPosition = FieldPosition.HEADER,
     ):
         self.name = name
-        self.values: list[str] = [val for val in values] if values is not None else []
+        self.values: list[str] = list(values) if values is not None else []
         self.kind = kind
 
     def add(self, value: str) -> None:
@@ -99,7 +99,7 @@ def __init__(
         :param encoding: The string encoding to be used when converting the ``Field``
         name and value from ``str`` to ``bytes`` for transmission.
         """
-        init_fields = [fld for fld in initial] if initial is not None else []
+        init_fields = list(initial) if initial is not None else []
         init_field_names = [self._normalize_field_name(fld.name) for fld in init_fields]
         fname_counter = Counter(init_field_names)
         repeated_names_exist = (
diff --git a/packages/smithy-http/src/smithy_http/aio/aiohttp.py b/packages/smithy-http/src/smithy_http/aio/aiohttp.py
index 6ac0464a4..04cafaed8 100644
--- a/packages/smithy-http/src/smithy_http/aio/aiohttp.py
+++ b/packages/smithy-http/src/smithy_http/aio/aiohttp.py
@@ -12,7 +12,7 @@
     import aiohttp
 
 try:
-    import aiohttp  # noqa: F811
+    import aiohttp
 
     HAS_AIOHTTP = True
 except ImportError:
diff --git a/packages/smithy-http/src/smithy_http/aio/auth/apikey.py b/packages/smithy-http/src/smithy_http/aio/auth/apikey.py
index 084d5e027..cacb81b0c 100644
--- a/packages/smithy-http/src/smithy_http/aio/auth/apikey.py
+++ b/packages/smithy-http/src/smithy_http/aio/auth/apikey.py
@@ -108,8 +108,8 @@ async def sign(
                 )
             case ApiKeyLocation.HEADER:
                 value = identity.api_key
-                if "scheme" in signing_properties and signing_properties["scheme"]:
-                    value = f"{signing_properties['scheme']} {value}"
+                if (scheme := signing_properties.get("scheme", None)) is not None:
+                    value = f"{scheme} {value}"
                 http_request.fields.set_field(
                     Field(name=signing_properties["name"], values=[value])
                 )
diff --git a/packages/smithy-http/src/smithy_http/aio/crt.py b/packages/smithy-http/src/smithy_http/aio/crt.py
index 6cb635a44..2dec88a06 100644
--- a/packages/smithy-http/src/smithy_http/aio/crt.py
+++ b/packages/smithy-http/src/smithy_http/aio/crt.py
@@ -18,8 +18,8 @@
     from awscrt import io as crt_io
 
 try:
-    from awscrt import http as crt_http  # noqa: F811
-    from awscrt import io as crt_io  # noqa: F811
+    from awscrt import http as crt_http
+    from awscrt import io as crt_io
 
     HAS_CRT = True
 except ImportError:
@@ -57,7 +57,7 @@ def _initialize_default_loop(self) -> "crt_io.ClientBootstrap":
 class AWSCRTHTTPResponse(http_aio_interfaces.HTTPResponse):
     def __init__(self) -> None:
         _assert_crt()
-        self._stream: "crt_http.HttpClientStream | None" = None
+        self._stream: crt_http.HttpClientStream | None = None
         self._status_code_future: Future[int] = Future()
         self._headers_future: Future[Fields] = Future()
         self._chunk_futures: list[Future[bytes]] = []
diff --git a/packages/smithy-http/src/smithy_http/aio/interfaces/auth.py b/packages/smithy-http/src/smithy_http/aio/interfaces/auth.py
index 8c1e52624..0a40a8dad 100644
--- a/packages/smithy-http/src/smithy_http/aio/interfaces/auth.py
+++ b/packages/smithy-http/src/smithy_http/aio/interfaces/auth.py
@@ -23,8 +23,6 @@
 class SigningProperties(TypedDict):
     """Additional properties loaded to modify the signing process."""
 
-    ...
-
 
 SigningPropertiesType = TypeVar("SigningPropertiesType", bound=SigningProperties)
 SigningPropertiesType_contra = TypeVar(
diff --git a/packages/smithy-http/src/smithy_http/aio/restjson.py b/packages/smithy-http/src/smithy_http/aio/restjson.py
index f7396c92e..8ee54c923 100644
--- a/packages/smithy-http/src/smithy_http/aio/restjson.py
+++ b/packages/smithy-http/src/smithy_http/aio/restjson.py
@@ -5,10 +5,12 @@
 from smithy_core.documents import DocumentValue
 from smithy_core.utils import expect_type
 
-from ..restjson import _REST_JSON_CODE_HEADER  # pyright: ignore[reportPrivateUsage]
-from ..restjson import _REST_JSON_CODE_KEYS  # pyright: ignore[reportPrivateUsage]
-from ..restjson import _REST_JSON_MESSAGE_KEYS  # pyright: ignore[reportPrivateUsage]
-from ..restjson import RestJsonErrorInfo
+from ..restjson import (
+    _REST_JSON_CODE_HEADER,  # pyright: ignore[reportPrivateUsage]
+    _REST_JSON_CODE_KEYS,  # pyright: ignore[reportPrivateUsage]
+    _REST_JSON_MESSAGE_KEYS,  # pyright: ignore[reportPrivateUsage]
+    RestJsonErrorInfo,
+)
 from .interfaces import HTTPResponse
 
 
diff --git a/packages/smithy-http/tests/integration/aio/test_crt.py b/packages/smithy-http/tests/integration/aio/test_crt.py
index caed7c7ac..54072546a 100644
--- a/packages/smithy-http/tests/integration/aio/test_crt.py
+++ b/packages/smithy-http/tests/integration/aio/test_crt.py
@@ -12,9 +12,7 @@ async def test_basic_request_local(sample_request: HTTPRequest) -> None:
     session = AWSCRTHTTPClient(client_config=config)
     response = await session.send(request=sample_request)
     assert response.status == 200
-    print(f"{response=}")
     body = await response.consume_body_async()
-    print(f"{body=}")
     assert b"aws" in body
 
 
diff --git a/packages/smithy-json/pyproject.toml b/packages/smithy-json/pyproject.toml
index 3f7c971b3..16d5e3eaf 100644
--- a/packages/smithy-json/pyproject.toml
+++ b/packages/smithy-json/pyproject.toml
@@ -17,3 +17,6 @@ build-backend = "hatchling.build"
 exclude = [
   "tests",
 ]
+
+[tool.ruff]
+src = ["src"]
diff --git a/packages/smithy-json/src/smithy_json/_private/documents.py b/packages/smithy-json/src/smithy_json/_private/documents.py
index 2fb0b66a2..30d92f88c 100644
--- a/packages/smithy-json/src/smithy_json/_private/documents.py
+++ b/packages/smithy-json/src/smithy_json/_private/documents.py
@@ -121,7 +121,7 @@ def _wrap_map(self, value: Mapping[str, DocumentValue]) -> dict[str, "Document"]
         if self._schema.shape_type not in (ShapeType.STRUCTURE, ShapeType.UNION):
             return super()._wrap_map(value)
 
-        result: dict[str, "Document"] = {}
+        result: dict[str, Document] = {}
         for k, v in value.items():
             member_name = self._json_names.get(k, k)
             result[member_name] = self._new_document(
diff --git a/packages/smithy-json/tests/unit/__init__.py b/packages/smithy-json/tests/unit/__init__.py
index d82feb010..92c71b7b2 100644
--- a/packages/smithy-json/tests/unit/__init__.py
+++ b/packages/smithy-json/tests/unit/__init__.py
@@ -1,5 +1,5 @@
 from dataclasses import dataclass
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from decimal import Decimal
 from typing import Any, Self
 
@@ -314,7 +314,7 @@ def _read_optional_map(k: str, d: ShapeDeserializer):
     (Decimal("1.1"), b"1.1"),
     (b"foo", b'"Zm9v"'),
     ("foo", b'"foo"'),
-    (datetime(2024, 5, 15, tzinfo=timezone.utc), b'"2024-05-15T00:00:00Z"'),
+    (datetime(2024, 5, 15, tzinfo=UTC), b'"2024-05-15T00:00:00Z"'),
     (None, b"null"),
     (["foo"], b'["foo"]'),
     ({"foo": "bar"}, b'{"foo":"bar"}'),
@@ -328,19 +328,19 @@ def _read_optional_map(k: str, d: ShapeDeserializer):
     (SerdeShape(string_member="foo"), b'{"stringMember":"foo"}'),
     (SerdeShape(json_name_member="foo"), b'{"jsonName":"foo"}'),
     (
-        SerdeShape(timestamp_member=datetime(2024, 5, 15, tzinfo=timezone.utc)),
+        SerdeShape(timestamp_member=datetime(2024, 5, 15, tzinfo=UTC)),
         b'{"timestampMember":"2024-05-15T00:00:00Z"}',
     ),
     (
-        SerdeShape(date_time_member=datetime(2024, 5, 15, tzinfo=timezone.utc)),
+        SerdeShape(date_time_member=datetime(2024, 5, 15, tzinfo=UTC)),
         b'{"dateTimeMember":"2024-05-15T00:00:00Z"}',
     ),
     (
-        SerdeShape(http_date_member=datetime(2024, 5, 15, tzinfo=timezone.utc)),
+        SerdeShape(http_date_member=datetime(2024, 5, 15, tzinfo=UTC)),
         b'{"httpDateMember":"Wed, 15 May 2024 00:00:00 GMT"}',
     ),
     (
-        SerdeShape(epoch_seconds_member=datetime(2024, 5, 15, tzinfo=timezone.utc)),
+        SerdeShape(epoch_seconds_member=datetime(2024, 5, 15, tzinfo=UTC)),
         b'{"epochSecondsMember":1715731200}',
     ),
     (SerdeShape(document_member=Document(None)), b'{"documentMember":null}'),
@@ -369,26 +369,26 @@ def _read_optional_map(k: str, d: ShapeDeserializer):
     (Document("foo", schema=STRING), b'"foo"'),
     (Document("foo", schema=DOCUMENT), b'"foo"'),
     (
-        Document(datetime(2024, 5, 15, tzinfo=timezone.utc), schema=TIMESTAMP),
+        Document(datetime(2024, 5, 15, tzinfo=UTC), schema=TIMESTAMP),
         b'"2024-05-15T00:00:00Z"',
     ),
     (
         Document(
-            datetime(2024, 5, 15, tzinfo=timezone.utc),
+            datetime(2024, 5, 15, tzinfo=UTC),
             schema=SCHEMA.members["dateTimeMember"],
         ),
         b'"2024-05-15T00:00:00Z"',
     ),
     (
         Document(
-            datetime(2024, 5, 15, tzinfo=timezone.utc),
+            datetime(2024, 5, 15, tzinfo=UTC),
             schema=SCHEMA.members["httpDateMember"],
         ),
         b'"Wed, 15 May 2024 00:00:00 GMT"',
     ),
     (
         Document(
-            datetime(2024, 5, 15, tzinfo=timezone.utc),
+            datetime(2024, 5, 15, tzinfo=UTC),
             schema=SCHEMA.members["epochSecondsMember"],
         ),
         b"1715731200",
@@ -409,7 +409,7 @@ def _read_optional_map(k: str, d: ShapeDeserializer):
         (Document(1.1, schema=DOCUMENT), b"1.1"),
         (Document(b"foo", schema=DOCUMENT), b'"Zm9v"'),
         (
-            Document(datetime(2024, 5, 15, tzinfo=timezone.utc), schema=DOCUMENT),
+            Document(datetime(2024, 5, 15, tzinfo=UTC), schema=DOCUMENT),
             b'"2024-05-15T00:00:00Z"',
         ),
     ]
diff --git a/pyproject.toml b/pyproject.toml
index 6bdb5f1b1..80da06ae7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -46,12 +46,11 @@ black = true
 target-version = "py312"
 
 [tool.ruff.lint]
-# candidates: C4, DTZ, EM, INP, ISC, PERF, PIE, RUF, SIM118, SIM401, SLOT
+# candidates: DTZ, EM, INP, ISC, PERF, SIM118, SIM401, SLOT
 # perhaps in the future: N, PYI, TC, TID
 # probably not, a lot of work: DOC, D, PL, TRY
 
-# TODO: I, T, UP
-select = [ "ASYNC", "E1", "E4", "E7", "E9", "F", "FURB", "G", "LOG", "S" ]
+select = [ "ASYNC", "C4", "E1", "E4", "E7", "E9", "F", "FURB", "G", "I", "LOG", "PIE", "RUF", "S", "T", "UP" ]
 exclude = [ "packages/smithy-core/src/smithy_core/rfc3986.py" ]
 
 [tool.ruff.lint.per-file-ignores]