diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 0000000..3bd58a5
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,3 @@
+## 2024-05-24 - Memoize deterministic regex compilations and lexicon generation in text-processing pipelines
+**Learning:** In NLP or text-processing pipelines (e.g., within `openmed.clinical`), deterministic operations like regex compilations (`re.compile`) and lexicon generation are extremely expensive if called repeatedly per string evaluation. Without memoization, functions like `_compiled_context_lexicon` cause severe performance bottlenecks during span evaluations.
+**Action:** Always memoize deterministic regex compilations and lexicon generation (e.g., using `@functools.lru_cache`) when they are repeatedly called per string or span evaluation, provided the return type is immutable (e.g., a frozen dataclass).
diff --git a/openmed/openmed/clinical/context.py b/openmed/openmed/clinical/context.py
index 9fd11df..e78f5ad 100644
--- a/openmed/openmed/clinical/context.py
+++ b/openmed/openmed/clinical/context.py
@@ -35,6 +35,7 @@
 
 from __future__ import annotations
 
+import functools
 import re
 from collections.abc import Iterable, Iterator, Mapping, Sequence
 from dataclasses import dataclass, replace
@@ -154,6 +155,7 @@ class _CompiledContextLexicon:
     backward_context_cues: frozenset[str]
 
 
+@functools.lru_cache
 def _compiled_context_lexicon(language: str | None = None) -> _CompiledContextLexicon:
     lexicon = get_clinical_cue_lexicon(language)
     token_boundaries = lexicon.token_boundaries