diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 0000000..3d9bf00
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,3 @@
+## 2024-05-18 - Missing Memoization for Regex Compilations
+**Learning:** `_compiled_context_lexicon` function inside `openmed/openmed/clinical/context.py` compiles multiple heavy regular expressions dynamically without memoization. The function is called for every span context resolution (`resolve_temporality`, `resolve_uncertainty`, etc), leading to severe performance bottlenecks.
+**Action:** Always memoize deterministic regex compilations and lexicon generation in NLP pipelines (e.g. `openmed.clinical`) using `@functools.lru_cache` to prevent bottlenecks during repeated string/span evaluations. Make sure to only cache hashable parameters.
diff --git a/openmed/openmed/clinical/context.py b/openmed/openmed/clinical/context.py
index 9fd11df..ceacbcc 100644
--- a/openmed/openmed/clinical/context.py
+++ b/openmed/openmed/clinical/context.py
@@ -35,7 +35,9 @@
 
 from __future__ import annotations
 
+import functools
 import re
+import types
 from collections.abc import Iterable, Iterator, Mapping, Sequence
 from dataclasses import dataclass, replace
 from datetime import date
@@ -154,6 +156,7 @@ class _CompiledContextLexicon:
     backward_context_cues: frozenset[str]
 
 
+@functools.lru_cache(maxsize=None)
 def _compiled_context_lexicon(language: str | None = None) -> _CompiledContextLexicon:
     lexicon = get_clinical_cue_lexicon(language)
     token_boundaries = lexicon.token_boundaries
@@ -195,7 +198,7 @@ def _compiled_context_lexicon(language: str | None = None) -> _CompiledContextLe
             ),
             token_boundaries=token_boundaries,
         ),
-        category_by_text=_cue_category_lookup(lexicon),
+        category_by_text=types.MappingProxyType(_cue_category_lookup(lexicon)),
         backward_context_cues=frozenset(
             _normalize_cue_text(cue) for cue in lexicon.backward
         ),