diff --git a/git_theta/async_utils.py b/git_theta/async_utils.py
index 40879ea..2d65c9a 100644
--- a/git_theta/async_utils.py
+++ b/git_theta/async_utils.py
@@ -4,8 +4,11 @@
 import dataclasses
 import functools
 import sys
+from concurrent.futures import thread
 from typing import Any, Awaitable, Dict, Optional, Sequence, Tuple, TypeVar, Union
 
+import numba
+import numba.misc.numba_sysinfo
 import six
 
 if sys.version_info >= (3, 8):
@@ -14,6 +17,42 @@
     from typing_extensions import Protocol
 
 
+class Asyncify:
+    """Wrap sync functions for use in async."""
+
+    def __init__(self, *args, **kwargs):
+        self.executor = thread.ThreadPoolExecutor(*args, **kwargs)
+        # Adapted from https://github.com/numba/numba/blob/d44573b43dec9a7b66e9a0d24ef8db94c3dc346c/numba/misc/numba_sysinfo.py#L459
+        try:
+            # check import is ok, this means the DSO linkage is working
+            from numba.np.ufunc import tbbpool  # NOQA
+
+            # check that the version is compatible, this is a check performed at
+            # runtime (well, compile time), it will also ImportError if there's
+            # a problem.
+            from numba.np.ufunc.parallel import _check_tbb_version_compatible
+
+            numba.misc.numba_sysifo._check_tbb_version_compatible()
+            self.threadsafe = True
+        except ImportError as e:
+            try:
+                from numba.np.ufunc import omppool
+
+                self.threadsafe = True
+            except ImportError as e:
+                self.threadsafe = False
+        numba.config.THREADING_LAYER = "threadsafe" if self.threadsafe else "default"
+
+    async def __call__(self, fn, *args, **kwargs):
+        # If numba is thread safe then do it async!
+        if self.threadsafe:
+            return await asyncio.wrap_future(self.executor.submit(fn, *args, **kwargs))
+        return fn(*args, **kwargs)
+
+
+asyncify = Asyncify()
+
+
 def run(*args, **kwargs):
     """Run an awaitable to completion, dispatch based on python version."""
     if sys.version_info < (3, 8):
diff --git a/git_theta/git_utils.py b/git_theta/git_utils.py
index d36b598..a1586c2 100644
--- a/git_theta/git_utils.py
+++ b/git_theta/git_utils.py
@@ -2,6 +2,7 @@
 
 import filecmp
 import fnmatch
+import functools
 import io
 import json
 import logging
@@ -228,6 +229,7 @@ def remove_file(f, repo):
         repo.git.rm(f)
 
 
+@functools.lru_cache(32)
 def get_file_version(repo, path, commit_hash):
     path = get_relative_path_from_root(repo, path)
     try:
diff --git a/git_theta/scripts/git_theta_filter.py b/git_theta/scripts/git_theta_filter.py
index 6d8a392..1f26f80 100755
--- a/git_theta/scripts/git_theta_filter.py
+++ b/git_theta/scripts/git_theta_filter.py
@@ -64,7 +64,9 @@ async def _clean(param_keys, new_param):
         # Get the metadata from the previous version of the parameter
         param_metadata = prev_metadata.get(param_keys)
         # Create new metadata from the current value
-        new_tensor_metadata = metadata.TensorMetadata.from_tensor(new_param)
+        new_tensor_metadata = await async_utils.asyncify(
+            metadata.TensorMetadata.from_tensor, new_param
+        )
 
         # If the parameter tensor has not changed, just keep the metadata the same
         # TODO: Encapsulate this parameter check within an equality check.
diff --git a/git_theta/updates/base.py b/git_theta/updates/base.py
index a04917d..573e03d 100644
--- a/git_theta/updates/base.py
+++ b/git_theta/updates/base.py
@@ -14,7 +14,7 @@
 
 import numpy as np
 
-from git_theta import checkpoints, git_utils, lsh, metadata, params, utils
+from git_theta import async_utils, checkpoints, git_utils, lsh, metadata, params, utils
 from git_theta.lsh.types import Signature
 
 Parameter = np.ndarray
@@ -100,6 +100,7 @@ async def get_previous_metadata(
         logging.debug(
             f"Getting metadata for {'/'.join(param_keys)} from commit {last_commit}"
         )
+        # Note: I tried to asyncify this and it seems to cause deadlock.
         last_metadata_obj = git_utils.get_file_version(repo, path, last_commit)
         last_metadata = metadata.Metadata.from_file(last_metadata_obj.data_stream)
         last_param_metadata = last_metadata.flatten()[param_keys]
@@ -179,7 +180,7 @@ async def write(
             # Calculate and hash the *new* value so that we can update the
             # metadata when using side-loaded information.
             new_value = await self.apply_update(update_value, previous_value)
-            new_hash = lsh.get_lsh().hash(new_value)
+            new_hash = await async_utils.asyncify(lsh.get_lsh().hash, new_value)
             return await self.write_update(update_value), new_hash
         else:
             update_value = await self.calculate_update(param, previous_value)