diff --git a/.github/workflows/run_tests.yml b/.github/workflows/run_tests.yml
index cefb623a..9e6b7f0c 100644
--- a/.github/workflows/run_tests.yml
+++ b/.github/workflows/run_tests.yml
@@ -20,12 +20,12 @@ jobs:
         # test with oldest and latest supported Python versions
         # NOTE: If bumping the minimum Python version here, also do it in
         # ruff.toml, setup.py and other CI files as well.
-        python-version: ["3.10", "3.12"]
+        python-version: ["3.10", "3.13"]
         runtime-deps: ["latest"]
 
         include:
           - os: ubuntu-latest
-            python-version: "3.12"
+            python-version: "3.10"
             runtime-deps: "oldest"
 
       fail-fast: false
@@ -199,7 +199,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-24.04]
-        python-version: ["3.12"]
+        python-version: ["3.13"]
 
         arch: ["x64"]
         docker-engine: ["docker"]
@@ -214,18 +214,18 @@ jobs:
           # Test on arm to ensure compatibility with Apple M1 chips
           # (OSX runners don't have access to Docker so we use Linux ARM runners instead)
           - os: "ubuntu-24.04"
-            python-version: "3.12"
+            python-version: "3.13"
             arch: "arm"
             docker-engine: "docker"
             unit-tesseract: "base"
           - os: "ubuntu-24.04"
-            python-version: "3.12"
+            python-version: "3.13"
             arch: "arm"
             docker-engine: "docker"
             unit-tesseract: "pyvista-arm64"
           # Run tests using Podman
           - os: "ubuntu-24.04"
-            python-version: "3.12"
+            python-version: "3.13"
             arch: "x64"
             docker-engine: "podman"
             unit-tesseract: "base"
diff --git a/examples/py39/tesseract_api.py b/examples/py310/tesseract_api.py
similarity index 88%
rename from examples/py39/tesseract_api.py
rename to examples/py310/tesseract_api.py
index b786d49e..8cf9b0c7 100644
--- a/examples/py39/tesseract_api.py
+++ b/examples/py310/tesseract_api.py
@@ -25,10 +25,10 @@ class OutputSchema(BaseModel):
 
 
 def apply(inputs: InputSchema) -> OutputSchema:
-    # Ensure that the Python version is what we expect (3.9)
+    # Ensure that the Python version is what we expect (3.10)
     import sys
 
-    assert sys.version_info[:2] == (3, 9)
+    assert sys.version_info[:2] == (3, 10)
     return OutputSchema(bar=0)
 
 
diff --git a/examples/py310/tesseract_config.yaml b/examples/py310/tesseract_config.yaml
new file mode 100644
index 00000000..7ff5dc07
--- /dev/null
+++ b/examples/py310/tesseract_config.yaml
@@ -0,0 +1,7 @@
+name: "py310"
+version: "0.1.0"
+description: |
+  Empty Tesseract that requires Python 3.10 (set through a custom Docker image).
+
+build_config:
+  base_image: "python:3.10-slim-bookworm"
diff --git a/examples/py39/tesseract_config.yaml b/examples/py39/tesseract_config.yaml
deleted file mode 100644
index 86d9a54f..00000000
--- a/examples/py39/tesseract_config.yaml
+++ /dev/null
@@ -1,7 +0,0 @@
-name: "py39"
-version: "0.1.0"
-description: |
-  Empty Tesseract that requires Python 3.9 (set through a custom Docker image).
-
-build_config:
-  base_image: "python:3.9-slim-bookworm"
diff --git a/examples/qp_solve/tesseract_api.py b/examples/qp_solve/tesseract_api.py
index 20a62234..fd157528 100644
--- a/examples/qp_solve/tesseract_api.py
+++ b/examples/qp_solve/tesseract_api.py
@@ -4,7 +4,6 @@
 # Tesseract API module for lp_solve
 # Generated by tesseract 0.9.0 on 2025-06-04T13:11:17.208977
 import functools
-from typing import Optional
 
 import jax
 import jax.numpy as jnp
@@ -23,29 +22,29 @@ class InputSchema(BaseModel):
     Q: Differentiable[Array[(None, None), Float32]] = Field(
         description="Quadratic cost matrix Q for the quadratic program."
     )
-    q: Optional[Differentiable[Array[(None,), Float32]]] = Field(
+    q: Differentiable[Array[(None,), Float32]] | None = Field(
         description="Linear cost vector q for the quadratic program.", default=None
     )
-    A: Optional[Differentiable[Array[(None, None), Float32]]] = Field(
+    A: Differentiable[Array[(None, None), Float32]] | None = Field(
         default=None,
         description="Linear equality constraint matrix A for the quadratic program.",
     )
-    b: Optional[Differentiable[Array[(None,), Float32]]] = Field(
+    b: Differentiable[Array[(None,), Float32]] | None = Field(
         default=None,
         description="Linear equality constraint rhs b for the quadratic program.",
     )
-    G: Optional[Differentiable[Array[(None, None), Float32]]] = Field(
+    G: Differentiable[Array[(None, None), Float32]] | None = Field(
         description="Linear inequality constraint matrix G for the quadratic program.",
         default=None,
     )
-    h: Optional[Differentiable[Array[(None,), Float32]]] = Field(
+    h: Differentiable[Array[(None,), Float32]] | None = Field(
         description="Linear inequality constraint rhs h for the quadratic program.",
         default=None,
     )
-    solver_tol: Optional[Float32] = Field(
+    solver_tol: Float32 | None = Field(
         description="Tolerance for the solver convergence.", default=1e-4
     )
-    target_kappa: Optional[Float32] = Field(
+    target_kappa: Float32 | None = Field(
         description="QPAX parameter for QP relaxation.", default=1e-3
     )
 
diff --git a/examples/univariate/optimize.py b/examples/univariate/optimize.py
index b0c4a1a2..66faf5d3 100644
--- a/examples/univariate/optimize.py
+++ b/examples/univariate/optimize.py
@@ -37,6 +37,6 @@ def rosenbrock_gradient(x: np.ndarray) -> np.ndarray:
     callback=lambda xs: trajectory.append(xs.tolist()),
 )
 
-anim = make_animation(*list(zip(*trajectory)))
+anim = make_animation(*list(zip(*trajectory, strict=True)))
 # anim.save("rosenbrock_optimization.gif", writer="pillow", fps=2, dpi=150)
 plt.show()
diff --git a/pyproject.toml b/pyproject.toml
index 8ae79bf7..cab1dfcc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -59,6 +59,7 @@ filterwarnings = [
     "ignore:numpy.ufunc size changed",
     # sometimes, dependencies leak resources
     "ignore:.*socket\\.socket.*:pytest.PytestUnraisableExceptionWarning",
+    "ignore:.*sqlite3\\.Connection.*:pytest.PytestUnraisableExceptionWarning",
 ]
 
 [tool.coverage.run]
diff --git a/ruff.toml b/ruff.toml
index b20d25c1..dcf11c66 100644
--- a/ruff.toml
+++ b/ruff.toml
@@ -1,6 +1,5 @@
 # Set to the lowest supported Python version.
-# !! tesseract_runtime still supports Python 3.9 !!
-target-version = "py39"
+target-version = "py310"
 
 # Set the target line length for formatting.
 line-length = 88
diff --git a/tesseract_core/runtime/array_encoding.py b/tesseract_core/runtime/array_encoding.py
index 460062f0..9f692e12 100644
--- a/tesseract_core/runtime/array_encoding.py
+++ b/tesseract_core/runtime/array_encoding.py
@@ -4,7 +4,7 @@
 import re
 from collections.abc import Sequence
 from pathlib import Path
-from typing import Annotated, Any, Literal, Optional, Union, get_args
+from typing import Annotated, Any, Literal, get_args
 from uuid import uuid4
 
 import numpy as np
@@ -45,8 +45,8 @@
     "complex128",
 ]
 EllipsisType = type(Ellipsis)
-ArrayLike = Union[np.ndarray, np.number, np.bool_]
-ShapeType = Union[tuple[Optional[int], ...], EllipsisType]
+ArrayLike = np.ndarray | np.number | np.bool_
+ShapeType = tuple[int | None, ...] | EllipsisType
 
 MAX_BINREF_BUFFER_SIZE = 100 * 1024 * 1024  # 100 MB
 
@@ -94,12 +94,12 @@ class EncodedArrayModel(BaseModel):
     object_type: Literal["array"]
     shape: tuple[PositiveInt, ...]
     dtype: AllowedDtypes
-    data: Union[BinrefArrayData, Base64ArrayData, JsonArrayData]
+    data: BinrefArrayData | Base64ArrayData | JsonArrayData
     model_config = ConfigDict(extra="forbid")
 
 
 def get_array_model(
-    expected_shape: ShapeType, expected_dtype: Optional[str], flags: Sequence[str]
+    expected_shape: ShapeType, expected_dtype: str | None, flags: Sequence[str]
 ) -> type[EncodedArrayModel]:
     """Create a Pydantic model for an encoded array that does validation on the given expected shape and dtype."""
     if expected_dtype is None:
@@ -177,7 +177,7 @@ def get_array_model(
         ),
         # Choose the appropriate data structure based on the encoding
         "data": (
-            Union[BinrefArrayData, Base64ArrayData, JsonArrayData],
+            BinrefArrayData | Base64ArrayData | JsonArrayData,
             Field(discriminator="encoding"),
         ),
         "model_config": (ConfigDict, config),
@@ -203,12 +203,12 @@ def get_array_model(
 
 
 def _dump_binref_arraydict(
-    arr: Union[np.ndarray, np.number, np.bool_],
-    base_dir: Union[Path, str],
-    subdir: Optional[Union[Path, str]],
+    arr: np.ndarray | np.number | np.bool_,
+    base_dir: Path | str,
+    subdir: Path | str | None,
     current_binref_uuid: str,
     max_file_size: int = MAX_BINREF_BUFFER_SIZE,
-) -> tuple[dict[str, Union[str, dict[str, str]]], str]:
+) -> tuple[dict[str, str | dict[str, str]], str]:
     """Dump array to json+binref encoded array dict.
 
     Writes a .bin file and returns json encoded data.
@@ -243,8 +243,8 @@ def _dump_binref_arraydict(
 
 
 def _dump_base64_arraydict(
-    arr: Union[np.ndarray, np.number, np.bool_],
-) -> dict[str, Union[str, dict[str, str]]]:
+    arr: np.ndarray | np.number | np.bool_,
+) -> dict[str, str | dict[str, str]]:
     """Dump array to json+base64 encoded array dict."""
     data = {
         "buffer": pybase64.b64encode(arr.tobytes()).decode(),
@@ -260,8 +260,8 @@ def _dump_base64_arraydict(
 
 
 def _dump_json_arraydict(
-    arr: Union[np.ndarray, np.number, np.bool_],
-) -> dict[str, Union[str, dict[str, str]]]:
+    arr: np.ndarray | np.number | np.bool_,
+) -> dict[str, str | dict[str, str]]:
     """Dump array to json encoded array dict."""
     data = {
         "buffer": arr.tolist(),
@@ -282,7 +282,7 @@ def _load_base64_arraydict(val: dict) -> np.ndarray:
     return np.frombuffer(buffer, dtype=val["dtype"]).reshape(val["shape"])
 
 
-def _load_binref_arraydict(val: dict, base_dir: Union[str, Path, None]) -> np.ndarray:
+def _load_binref_arraydict(val: dict, base_dir: str | Path | None) -> np.ndarray:
     """Load array from json+binref encoded array dict."""
     path_match = re.match(r"^(?P<path>.+?)(\:(?P<offset>\d+))?$", val["data"]["buffer"])
     if not path_match:
@@ -316,7 +316,7 @@ def _load_binref_arraydict(val: dict, base_dir: Union[str, Path, None]) -> np.nd
 
 
 def _coerce_shape_dtype(
-    arr: ArrayLike, expected_shape: ShapeType, expected_dtype: Optional[str]
+    arr: ArrayLike, expected_shape: ShapeType, expected_dtype: str | None
 ) -> ArrayLike:
     """Coerce the shape and dtype of the passed array to the expected values."""
     if expected_shape is Ellipsis:
@@ -363,7 +363,7 @@ def _coerce_shape_dtype(
 
 
 def python_to_array(
-    val: Any, expected_shape: ShapeType, expected_dtype: Optional[str]
+    val: Any, expected_shape: ShapeType, expected_dtype: str | None
 ) -> ArrayLike:
     """Convert a Python object to a NumPy array."""
     val = np.asarray(val, order="C")
@@ -380,7 +380,7 @@ def decode_array(
     val: EncodedArrayModel,
     info: ValidationInfo,
     expected_shape: ShapeType,
-    expected_dtype: Optional[str],
+    expected_dtype: str | None,
 ) -> ArrayLike:
     """Decode an EncodedArrayModel to a NumPy array."""
     from tesseract_core.runtime.config import get_config
@@ -422,8 +422,8 @@ def decode_array(
 
 
 def encode_array(
-    arr: ArrayLike, info: Any, expected_shape: ShapeType, expected_dtype: Optional[str]
-) -> Union[EncodedArrayModel, ArrayLike]:
+    arr: ArrayLike, info: Any, expected_shape: ShapeType, expected_dtype: str | None
+) -> EncodedArrayModel | ArrayLike:
     """Encode a NumPy array as an EncodedArrayModel."""
     from tesseract_core.runtime.config import get_config
 
diff --git a/tesseract_core/runtime/cli.py b/tesseract_core/runtime/cli.py
index 2319834a..ae611e18 100644
--- a/tesseract_core/runtime/cli.py
+++ b/tesseract_core/runtime/cli.py
@@ -16,7 +16,6 @@
     Annotated,
     Any,
     Literal,
-    Optional,
     get_args,
     get_origin,
 )
@@ -219,7 +218,7 @@ def check_gradients(
         ),
     ],
     input_paths: Annotated[
-        Optional[list[str]],
+        list[str] | None,
         typer.Option(
             "--input-paths",
             help="Paths to differentiable inputs to check gradients for.",
@@ -227,7 +226,7 @@ def check_gradients(
         ),
     ] = None,
     output_paths: Annotated[
-        Optional[list[str]],
+        list[str] | None,
         typer.Option(
             "--output-paths",
             help="Paths to differentiable outputs to check gradients for.",
@@ -235,7 +234,7 @@ def check_gradients(
         ),
     ] = None,
     endpoints: Annotated[
-        Optional[list[str]],
+        list[str] | None,
         typer.Option(
             "--endpoints",
             help="Endpoints to check gradients for.",
@@ -275,7 +274,7 @@ def check_gradients(
         ),
     ] = 10,
     seed: Annotated[
-        Optional[int],
+        int | None,
         typer.Option(
             "--seed",
             help="Seed for random number generator. If not set, a random seed is used.",
@@ -367,7 +366,7 @@ def serve(
 
 
 def _create_user_defined_cli_command(
-    app: typer.Typer, user_function: Callable, out_stream: Optional[io.TextIOBase]
+    app: typer.Typer, user_function: Callable, out_stream: io.TextIOBase | None
 ) -> None:
     """Creates a click command which sends requests to Tesseract endpoints.
 
@@ -459,9 +458,7 @@ def command_func():
     decorator(command_func)
 
 
-def _add_user_commands_to_cli(
-    app: typer.Typer, out_stream: Optional[io.IOBase]
-) -> None:
+def _add_user_commands_to_cli(app: typer.Typer, out_stream: io.IOBase | None) -> None:
     tesseract_package = get_tesseract_api()
     endpoints = create_endpoints(tesseract_package)
 
diff --git a/tesseract_core/runtime/core.py b/tesseract_core/runtime/core.py
index 25827898..f357637a 100644
--- a/tesseract_core/runtime/core.py
+++ b/tesseract_core/runtime/core.py
@@ -9,7 +9,7 @@
 from io import TextIOBase
 from pathlib import Path
 from types import ModuleType
-from typing import Any, TextIO, Union
+from typing import Any, TextIO
 
 from pydantic import BaseModel
 
@@ -22,9 +22,7 @@
 
 
 @contextmanager
-def redirect_fd(
-    from_: TextIO, to_: Union[TextIO, int]
-) -> Generator[TextIO, None, None]:
+def redirect_fd(from_: TextIO, to_: TextIO | int) -> Generator[TextIO, None, None]:
     """Redirect a file descriptor at OS level.
 
     Args:
@@ -49,7 +47,7 @@ def redirect_fd(
         orig_fd_file.close()
 
 
-def load_module_from_path(path: Union[Path, str]) -> ModuleType:
+def load_module_from_path(path: Path | str) -> ModuleType:
     """Load a module from a file path.
 
     Temporarily puts the module's parent folder on PYTHONPATH to ensure local imports work as expected.
diff --git a/tesseract_core/runtime/experimental.py b/tesseract_core/runtime/experimental.py
index f9c53b27..8f06912d 100644
--- a/tesseract_core/runtime/experimental.py
+++ b/tesseract_core/runtime/experimental.py
@@ -2,13 +2,11 @@
 # SPDX-License-Identifier: Apache-2.0
 
 import json
-from collections.abc import Iterator, Sequence
+from collections.abc import Callable, Iterator, Sequence
 from pathlib import Path
 from typing import (
     Annotated,
     Any,
-    Callable,
-    Union,
     get_args,
     get_origin,
 )
@@ -114,7 +112,7 @@ def __get_pydantic_core_schema__(
         Does most of the heavy lifting for validation and serialization.
         """
 
-        def create_sequence(maybe_path: Union[str, Sequence[Any]]) -> LazySequence:
+        def create_sequence(maybe_path: str | Sequence[Any]) -> LazySequence:
             """Expand a glob pattern into a LazySequence if needed."""
             validator = SchemaValidator(item_schema)
 
diff --git a/tesseract_core/runtime/file_interactions.py b/tesseract_core/runtime/file_interactions.py
index 69b48235..503be554 100644
--- a/tesseract_core/runtime/file_interactions.py
+++ b/tesseract_core/runtime/file_interactions.py
@@ -3,12 +3,12 @@
 
 import urllib.parse
 from pathlib import Path
-from typing import Any, Literal, Optional, Union, get_args
+from typing import Any, Literal, get_args
 
 import fsspec
 from pydantic import TypeAdapter
 
-PathLike = Union[str, Path]
+PathLike = str | Path
 
 supported_format_type = Literal["json", "json+base64", "json+binref"]
 SUPPORTED_FORMATS = get_args(supported_format_type)
@@ -17,8 +17,8 @@
 def output_to_bytes(
     obj: Any,
     format: supported_format_type,
-    base_dir: Optional[Union[str, Path]] = None,
-    binref_dir: Optional[Union[str, Path]] = None,
+    base_dir: str | Path | None = None,
+    binref_dir: str | Path | None = None,
 ) -> bytes:
     """Encode endpoint output to bytes in the given format.
 
diff --git a/tesseract_core/runtime/finite_differences.py b/tesseract_core/runtime/finite_differences.py
index 27c1c9e5..6230c643 100644
--- a/tesseract_core/runtime/finite_differences.py
+++ b/tesseract_core/runtime/finite_differences.py
@@ -2,16 +2,14 @@
 # SPDX-License-Identifier: Apache-2.0
 
 import traceback
-from collections.abc import Iterator, Sequence
+from collections.abc import Callable, Iterator, Sequence
 from functools import wraps
 from pathlib import Path
 from types import ModuleType
 from typing import (
     Any,
-    Callable,
     Literal,
     NamedTuple,
-    Optional,
     get_args,
 )
 
@@ -43,9 +41,9 @@ class GradientCheckResult(NamedTuple):
     in_path: str
     out_path: str
     idx: tuple[int, ...]
-    grad_val: Optional[ArrayLike]
-    ref_val: Optional[ArrayLike]
-    exception: Optional[str]
+    grad_val: ArrayLike | None
+    ref_val: ArrayLike | None
+    exception: str | None
 
 
 def get_input_schema(endpoint_function: Callable) -> type[BaseModel]:
@@ -297,7 +295,7 @@ def _sample_indices(
             continue
         n_evals = max(1, int(max_evals * np.prod(shape) / total_elements))
         idx_tuple = np.unravel_index(rng.choice(int(np.prod(shape)), n_evals), shape)
-        idx_per_input[path] = list(zip(*idx_tuple))
+        idx_per_input[path] = list(zip(*idx_tuple, strict=True))
 
     items_to_check = []
     for in_path in diff_inputs:
@@ -408,14 +406,14 @@ def check_gradients(
     api_module: ModuleType,
     inputs: dict[str, Any],
     *,
-    input_paths: Optional[Sequence[str]] = None,
-    output_paths: Optional[Sequence[str]] = None,
-    base_dir: Optional[Path] = None,
-    endpoints: Optional[Sequence[ADEndpointName]] = None,
+    input_paths: Sequence[str] | None = None,
+    output_paths: Sequence[str] | None = None,
+    base_dir: Path | None = None,
+    endpoints: Sequence[ADEndpointName] | None = None,
     max_evals: int = 1000,
     eps: float = 1e-4,
     rtol: float = 0.1,
-    seed: Optional[int] = None,
+    seed: int | None = None,
     show_progress: bool = True,
 ) -> Iterator[tuple[str, list[GradientCheckResult], int]]:
     """Check gradients of endpoints against a finite difference approximation.
diff --git a/tesseract_core/runtime/logs.py b/tesseract_core/runtime/logs.py
index 4376cab2..21c6d5d2 100644
--- a/tesseract_core/runtime/logs.py
+++ b/tesseract_core/runtime/logs.py
@@ -3,7 +3,8 @@
 
 import os
 import threading
-from typing import Any, Callable
+from collections.abc import Callable
+from typing import Any
 
 
 # NOTE: This is duplicated in `tesseract_core/sdk/logs.py`.
diff --git a/tesseract_core/runtime/meta/pyproject.toml b/tesseract_core/runtime/meta/pyproject.toml
index 08e98b54..7c029847 100644
--- a/tesseract_core/runtime/meta/pyproject.toml
+++ b/tesseract_core/runtime/meta/pyproject.toml
@@ -1,7 +1,7 @@
 [project]
 name = "tesseract_runtime"
 version = "0.1.0"
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 
 # NOTE: Upper bounds (<=) are periodically updated via .github/workflows/bump_lockfile.yml,
 # do not edit manually. To add constraints, use other operators (e.g. <, >=, ~=, ==) as needed.
diff --git a/tesseract_core/runtime/mpa.py b/tesseract_core/runtime/mpa.py
index fe3a0b5f..78fb5894 100644
--- a/tesseract_core/runtime/mpa.py
+++ b/tesseract_core/runtime/mpa.py
@@ -15,7 +15,7 @@
 from datetime import datetime
 from io import UnsupportedOperation
 from pathlib import Path
-from typing import Any, Optional, Union
+from typing import Any
 
 import requests
 
@@ -26,7 +26,7 @@
 class BaseBackend(ABC):
     """Base class for MPA backends."""
 
-    def __init__(self, base_dir: Optional[str] = None) -> None:
+    def __init__(self, base_dir: str | None = None) -> None:
         if base_dir is None:
             base_dir = get_config().output_path
         self.log_dir = Path(base_dir) / "logs"
@@ -38,7 +38,7 @@ def log_parameter(self, key: str, value: Any) -> None:
         pass
 
     @abstractmethod
-    def log_metric(self, key: str, value: float, step: Optional[int] = None) -> None:
+    def log_metric(self, key: str, value: float, step: int | None = None) -> None:
         """Log a metric."""
         pass
 
@@ -61,7 +61,7 @@ def end_run(self) -> None:
 class FileBackend(BaseBackend):
     """MPA backend that writes to local files."""
 
-    def __init__(self, base_dir: Optional[str] = None) -> None:
+    def __init__(self, base_dir: str | None = None) -> None:
         super().__init__(base_dir)
         # Initialize log files
         self.params_file = self.log_dir / "parameters.json"
@@ -84,7 +84,7 @@ def log_parameter(self, key: str, value: Any) -> None:
         with open(self.params_file, "w") as f:
             json.dump(self.parameters, f, indent=2, default=str)
 
-    def log_metric(self, key: str, value: float, step: Optional[int] = None) -> None:
+    def log_metric(self, key: str, value: float, step: int | None = None) -> None:
         """Log a metric to CSV file."""
         timestamp = datetime.now().isoformat()
         step_value = (
@@ -126,7 +126,7 @@ def end_run(self) -> None:
 class MLflowBackend(BaseBackend):
     """MPA backend that writes to an MLflow tracking server."""
 
-    def __init__(self, base_dir: Optional[str] = None) -> None:
+    def __init__(self, base_dir: str | None = None) -> None:
         super().__init__(base_dir)
         os.environ["GIT_PYTHON_REFRESH"] = (
             "quiet"  # Suppress potential MLflow git warnings
@@ -176,7 +176,7 @@ def log_parameter(self, key: str, value: Any) -> None:
         """Log a parameter to MLflow."""
         self.mlflow.log_param(key, value)
 
-    def log_metric(self, key: str, value: float, step: Optional[int] = None) -> None:
+    def log_metric(self, key: str, value: float, step: int | None = None) -> None:
         """Log a metric to MLflow."""
         self.mlflow.log_metric(key, value, step=step)
 
@@ -193,7 +193,7 @@ def end_run(self) -> None:
         self.mlflow.end_run()
 
 
-def _create_backend(base_dir: Optional[str]) -> BaseBackend:
+def _create_backend(base_dir: str | None) -> BaseBackend:
     """Create the appropriate backend based on environment."""
     config = get_config()
     if config.mlflow_tracking_uri:
@@ -222,7 +222,7 @@ def log_parameter(key: str, value: Any) -> None:
     _get_current_backend().log_parameter(key, value)
 
 
-def log_metric(key: str, value: float, step: Optional[int] = None) -> None:
+def log_metric(key: str, value: float, step: int | None = None) -> None:
     """Log a metric to the current run context."""
     _get_current_backend().log_metric(key, value, step)
 
@@ -233,7 +233,7 @@ def log_artifact(local_path: str) -> None:
 
 
 @contextmanager
-def redirect_stdio(logfile: Union[str, Path]) -> Generator[None, None, None]:
+def redirect_stdio(logfile: str | Path) -> Generator[None, None, None]:
     """Context manager for redirecting stdout and stderr to a custom pipe.
 
     Writes messages to both the original stderr and the given logfile.
@@ -270,7 +270,7 @@ def redirect_stdio(logfile: Union[str, Path]) -> Generator[None, None, None]:
 
 
 @contextmanager
-def start_run(base_dir: Optional[str] = None) -> Generator[None, None, None]:
+def start_run(base_dir: str | None = None) -> Generator[None, None, None]:
     """Context manager for starting and ending a run."""
     backend = _create_backend(base_dir)
     token = _current_backend.set(backend)
diff --git a/tesseract_core/runtime/schema_generation.py b/tesseract_core/runtime/schema_generation.py
index 2a76d1c4..6a3d77b4 100644
--- a/tesseract_core/runtime/schema_generation.py
+++ b/tesseract_core/runtime/schema_generation.py
@@ -2,7 +2,6 @@
 # SPDX-License-Identifier: Apache-2.0
 
 import re
-import sys
 import types
 from collections.abc import Callable, Iterable, Mapping, Sequence
 from copy import copy
@@ -11,7 +10,6 @@
     Any,
     ClassVar,
     Literal,
-    Optional,
     TypeVar,
     Union,
     get_args,
@@ -46,9 +44,7 @@
 
 # Python has funnily enough two union types now. See https://github.com/python/cpython/issues/105499
 # We check against both for compatibility with older versions of Python.
-UNION_TYPES = [Union]
-if sys.version_info >= (3, 10):
-    UNION_TYPES += [types.UnionType]
+UNION_TYPES = [Union, types.UnionType]
 
 
 def _construct_annotated(obj: Any, metadata: Iterable[Any]) -> Any:
@@ -69,7 +65,7 @@ def apply_function_to_model_tree(
     Schema: type[BaseModel],
     func: Callable[[type, tuple], type],
     model_prefix: str = "",
-    default_model_config: Optional[dict[str, Any]] = None,
+    default_model_config: dict[str, Any] | None = None,
 ) -> type[BaseModel]:
     """Apply a function to all leaves of a Pydantic model, recursing into containers + nested models.
 
@@ -171,7 +167,7 @@ def _recurse_over_model_tree(treeobj: Any, path: list[str]) -> Any:
             if not newargs:
                 return None
 
-            return Union[tuple(newargs)]
+            return Union[tuple(newargs)]  # noqa: UP007
 
         elif safe_issubclass(origin_type, Mapping):
             # Recurse into dict-likes
@@ -309,7 +305,7 @@ def create_abstract_eval_schema(
     fields replaced by ShapeDType objects.
     """
 
-    def replace_array_with_shapedtype(obj: T, _: Any) -> Union[T, type[ShapeDType]]:
+    def replace_array_with_shapedtype(obj: T, _: Any) -> T | type[ShapeDType]:
         if safe_issubclass(obj, PydanticArrayAnnotation):
             return ShapeDType.from_array_type(obj)
         return obj
@@ -363,7 +359,7 @@ def add_to_dict_if_diffable(obj: T, path: tuple) -> T:
     return diffable_paths
 
 
-def _path_to_pattern(path: Sequence[Union[str, object]]) -> str:
+def _path_to_pattern(path: Sequence[str | object]) -> str:
     """Return a type describing valid paths for all passed paths."""
     # Check if path includes sequence or dict indexing -- in this case, we can't use the
     # path as a literal and need to use a regex pattern instead.
@@ -434,10 +430,10 @@ def create_autodiff_schema(
         _path_to_pattern(path): obj for path, obj in diffable_output_paths.items()
     }
 
-    diffable_input_type = Union[
+    diffable_input_type = Union[  # noqa: UP007
         tuple(_pattern_to_type(p) for p in diffable_input_patterns)
     ]
-    diffable_output_type = Union[
+    diffable_output_type = Union[  # noqa: UP007
         tuple(_pattern_to_type(p) for p in diffable_output_patterns)
     ]
 
@@ -520,7 +516,7 @@ def result_validator(
 
                     if any(
                         s1 != s2
-                        for s1, s2 in zip(got_shape, expected_shape)
+                        for s1, s2 in zip(got_shape, expected_shape, strict=True)
                         if s2 is not None
                     ):
                         raise ValueError(
@@ -550,7 +546,7 @@ def result_validator(
 
                 if any(
                     s1 != s2
-                    for s1, s2 in zip(arr.shape, expected_shape)
+                    for s1, s2 in zip(arr.shape, expected_shape, strict=True)
                     if s2 is not None
                 ):
                     raise ValueError(
@@ -577,7 +573,7 @@ def result_validator(
 
                 if any(
                     s1 != s2
-                    for s1, s2 in zip(arr.shape, expected_shape)
+                    for s1, s2 in zip(arr.shape, expected_shape, strict=True)
                     if s2 is not None
                 ):
                     raise ValueError(
diff --git a/tesseract_core/runtime/schema_types.py b/tesseract_core/runtime/schema_types.py
index e3ce5f35..0816b825 100644
--- a/tesseract_core/runtime/schema_types.py
+++ b/tesseract_core/runtime/schema_types.py
@@ -1,7 +1,6 @@
 # Copyright 2025 Pasteur Labs. All Rights Reserved.
 # SPDX-License-Identifier: Apache-2.0
 
-import sys
 from abc import ABCMeta
 from enum import IntEnum
 from functools import partial
@@ -9,8 +8,7 @@
     TYPE_CHECKING,
     Annotated,
     Any,
-    Optional,
-    Union,
+    TypeAlias,
     get_args,
 )
 
@@ -33,15 +31,8 @@
     python_to_array,
 )
 
-if sys.version_info < (3, 10):
-    # TypeAlias is not available in Python < 3.10
-    AnnotatedType = type(Annotated[Any, Any])
-    EllipsisType = type(Ellipsis)
-else:
-    from typing import TypeAlias
-
-    AnnotatedType: TypeAlias = type(Annotated[Any, Any])
-    EllipsisType: TypeAlias = type(Ellipsis)
+AnnotatedType: TypeAlias = type(Annotated[Any, Any])
+EllipsisType: TypeAlias = type(Ellipsis)
 
 
 class ArrayFlags(IntEnum):
@@ -62,7 +53,7 @@ class ArrayAnnotationType(ABCMeta):
         MyArray[(2, 3), 'float32']
     """
 
-    expected_shape: Union[tuple[int, ...], EllipsisType]
+    expected_shape: tuple[int, ...] | EllipsisType
     expected_dtype: str
     flags: tuple[ArrayFlags]
 
@@ -95,7 +86,7 @@ class PydanticArrayAnnotation(metaclass=ArrayAnnotationType):
     """
 
     # These are class attributes that must be set when the class is created
-    expected_shape: Union[tuple[int, ...], EllipsisType]
+    expected_shape: tuple[int, ...] | EllipsisType
     expected_dtype: str
     flags: tuple[ArrayFlags]
 
@@ -235,8 +226,8 @@ def __init__(self, *args: Any, **kwargs: Any) -> None:
     def __class_getitem__(
         cls,
         key: tuple[
-            Union[tuple[Optional[int], ...], EllipsisType],
-            Union[ArrayAnnotationType, str, None],
+            tuple[int | None, ...] | EllipsisType,
+            ArrayAnnotationType | str | None,
         ],
     ) -> ArrayAnnotationType:
         """Create a new type annotation based on the given shape and dtype."""
@@ -316,8 +307,8 @@ class ShapeDType(BaseModel):
     def __class_getitem__(
         cls,
         key: tuple[
-            Union[tuple[Optional[int], ...], EllipsisType],
-            Union[AnnotatedType, str, None],
+            tuple[int | None, ...] | EllipsisType,
+            AnnotatedType | str | None,
         ],
     ) -> AnnotatedType:
         expected_shape, _ = _ensure_valid_shapedtype(*key)
@@ -329,14 +320,12 @@ def validate(shapedtype: ShapeDType) -> ShapeDType:
                 if expected_shape is Ellipsis:
                     return shapedtype
 
-                # TODO: replace this check with `zip(... strict=True)`
-                # once we stop supporting 3.9
                 if len(shape) != len(expected_shape):
                     raise ValueError(
                         f"Expected shape: {expected_shape}. Found: {shape}."
                     )
 
-                for actual, expected in zip(shape, expected_shape):
+                for actual, expected in zip(shape, expected_shape, strict=True):
                     if expected is not None and actual != expected:
                         raise ValueError(
                             f"Expected shape: {expected_shape}. Found: {shape}."
diff --git a/tesseract_core/runtime/serve.py b/tesseract_core/runtime/serve.py
index 1b4f6f70..ce18041a 100644
--- a/tesseract_core/runtime/serve.py
+++ b/tesseract_core/runtime/serve.py
@@ -3,9 +3,10 @@
 
 import inspect
 import uuid
+from collections.abc import Callable
 from functools import wraps
 from types import ModuleType
-from typing import Annotated, Any, Callable, Optional, Union
+from typing import Annotated, Any
 
 import uvicorn
 from fastapi import FastAPI, Header, Query, Response
@@ -21,7 +22,7 @@
 
 
 def create_response(
-    model: BaseModel, accept: str, base_dir: Optional[str], binref_dir: Optional[str]
+    model: BaseModel, accept: str, base_dir: str | None, binref_dir: str | None
 ) -> Response:
     """Create a response of the format specified by the Accept header."""
     config = get_config()
@@ -62,9 +63,7 @@ def wrap_endpoint(endpoint_func: Callable):
         ]
 
         @wraps(endpoint_func)
-        async def wrapper(
-            *args: Any, accept: str, run_id: Optional[str], **kwargs: Any
-        ):
+        async def wrapper(*args: Any, accept: str, run_id: str | None, **kwargs: Any):
             if run_id is None:
                 run_id = str(uuid.uuid4())
             output_path = get_config().output_path
@@ -88,13 +87,13 @@ async def wrapper(
                 "accept",
                 inspect.Parameter.POSITIONAL_OR_KEYWORD,
                 default=Header(default=None),
-                annotation=Union[str, None],
+                annotation=str | None,
             )
             run_id = inspect.Parameter(
                 "run_id",
                 inspect.Parameter.POSITIONAL_OR_KEYWORD,
                 default=None,
-                annotation=Annotated[Optional[str], Query(include_in_schema=False)],
+                annotation=Annotated[str | None, Query(include_in_schema=False)],
             )
             # Other header parameters common to computational endpoints
             # could be defined and appended here as well.
diff --git a/tesseract_core/runtime/tree_transforms.py b/tesseract_core/runtime/tree_transforms.py
index 7dd514f9..628fdf89 100644
--- a/tesseract_core/runtime/tree_transforms.py
+++ b/tesseract_core/runtime/tree_transforms.py
@@ -4,18 +4,18 @@
 import re
 from collections.abc import Callable, Iterable, Mapping, Sequence
 from copy import deepcopy
-from typing import Any, Literal, Optional, Union
+from typing import Any, Literal
 
 from pydantic import BaseModel
 
 
 def path_to_index_op(
     path: str,
-) -> Union[
-    tuple[Literal["seq"], int],
-    tuple[Literal["dict"], str],
-    tuple[Literal["getattr"], str],
-]:
+) -> (
+    tuple[Literal["seq"], int]
+    | tuple[Literal["dict"], str]
+    | tuple[Literal["getattr"], str]
+):
     """Converts a path string to a tuple of operation and index."""
     seq_idx_re = re.match(r"^\[(\d+)\]$", path)
     if seq_idx_re:
@@ -115,7 +115,7 @@ def _set_recursive(tree: Any, path: list[str], value: Any) -> Any:
 
 
 def flatten_with_paths(
-    tree: Union[Mapping, Sequence, BaseModel],
+    tree: Mapping | Sequence | BaseModel,
     include_paths: Iterable[str],
 ) -> dict[str, Any]:
     """Filter and flatten a nested PyTree by extracting only the specified paths.
@@ -131,8 +131,8 @@ def flatten_with_paths(
 def filter_func(
     func: Callable[[dict], dict],
     default_inputs: dict,
-    output_paths: Optional[Iterable[str]] = None,
-    input_paths: Optional[Sequence[str]] = None,
+    output_paths: Iterable[str] | None = None,
+    input_paths: Sequence[str] | None = None,
 ) -> Callable:
     """Modifies a function that operates on pytrees to operate on flat {path: value} or positional args instead.
 
@@ -153,12 +153,11 @@ def filter_func(
 
     def filtered_func(*args: Any) -> dict:
         if input_paths:
-            # TODO: replace this check with `zip(... strict=True)`
-            # once we stop supporting 3.9
-            assert len(input_paths) == len(args), (
-                f"Mismatch between number of given paths {len(input_paths)} and args {len(args)}."
-            )
-            new_inputs = dict(zip(input_paths, args))
+            if len(input_paths) != len(args):
+                raise ValueError(
+                    f"Mismatch between number of given paths {len(input_paths)} and args {len(args)}."
+                )
+            new_inputs = dict(zip(input_paths, args, strict=True))
         else:
             if len(args) != 1:
                 raise ValueError("Expected a single dictionary argument")
diff --git a/tesseract_core/sdk/api_parse.py b/tesseract_core/sdk/api_parse.py
index 2d695152..073694cf 100644
--- a/tesseract_core/sdk/api_parse.py
+++ b/tesseract_core/sdk/api_parse.py
@@ -4,7 +4,7 @@
 import ast
 import re
 from pathlib import Path
-from typing import Annotated, Literal, NamedTuple, Union
+from typing import Annotated, Literal, NamedTuple
 
 import yaml
 from pydantic import (
@@ -93,7 +93,7 @@ class CondaRequirements(BaseModel):
     model_config: ConfigDict = ConfigDict(extra="forbid")
 
 
-PythonRequirements = Union[PipRequirements, CondaRequirements]
+PythonRequirements = PipRequirements | CondaRequirements
 
 
 class TesseractBuildConfig(BaseModel, validate_assignment=True):
diff --git a/tesseract_core/sdk/logs.py b/tesseract_core/sdk/logs.py
index e22c2a43..e29ac6e1 100644
--- a/tesseract_core/sdk/logs.py
+++ b/tesseract_core/sdk/logs.py
@@ -7,9 +7,9 @@
 import sys
 import threading
 import warnings
-from collections.abc import Iterable
+from collections.abc import Callable, Iterable
 from types import ModuleType
-from typing import Any, Callable
+from typing import Any
 
 import typer
 from rich.console import Console
diff --git a/tests/endtoend_tests/test_examples.py b/tests/endtoend_tests/test_examples.py
index 26194f0d..fe2670d6 100644
--- a/tests/endtoend_tests/test_examples.py
+++ b/tests/endtoend_tests/test_examples.py
@@ -93,7 +93,7 @@ class Config:
             SampleRequest(endpoint="apply", payload={"inputs": {}}),
         ],
     ),
-    "py39": Config(
+    "py310": Config(
         test_with_random_inputs=True,
     ),
     "helloworld": Config(
diff --git a/tests/runtime_tests/test_tree_transforms.py b/tests/runtime_tests/test_tree_transforms.py
index a259a573..96f7bf2c 100644
--- a/tests/runtime_tests/test_tree_transforms.py
+++ b/tests/runtime_tests/test_tree_transforms.py
@@ -598,7 +598,7 @@ def test_filter_func_positional_args_mismatch(self, sample_tree, sample_func):
         filtered_func = filter_func(sample_func, sample_tree, input_paths=input_paths)
 
         # Wrong number of arguments
-        with pytest.raises(AssertionError, match="Mismatch between number"):
+        with pytest.raises(ValueError, match="Mismatch between number"):
             filtered_func("hello")  # Missing second argument
 
     def test_filter_func_dict_input_wrong_args(self, sample_tree, sample_func):