⚡ Bolt: Cache lowercased strings outside loops to prevent redundant O(N) allocations

.jules/bolt.md

@@ -13,3 +13,7 @@
 ## 2025-02-18 - Regex Pre-compilation in Hot Paths
 **Learning:** Re-compiling regexes inside a frequently called function (like `latex_escape` which runs for every string) creates significant overhead. Pre-compiling them at module level yielded a ~3.2x speedup.
 **Action:** Always look for regex compilations inside loops or frequently called functions and move them to module level constants.
+
+## 2026-07-25 - Redundant Lowercasing in Generator Expressions
+**Learning:** In Python, calling methods like `.lower()` on strings inside a comprehension or generator expression that iterates over the same text multiple times (e.g., `[kw for kw in items if kw in text.lower()]`) results in the `.lower()` operation being evaluated repeatedly for every iteration. This causes unnecessary $O(N)$ memory allocations and CPU overhead, especially on large strings.
+**Action:** Cache the result of such operations outside the loop or generator expression (e.g., `text_lower = text.lower()`) and use the cached variable inside the comprehension.

cli/generators/ats_generator.py

@@ -407,7 +407,9 @@ def _check_readability(self, resume_data: Dict[str, Any]) -> ATSCategoryScore:
             "improved",
             "achieved",
         ]
-        action_verb_count = sum(1 for verb in action_verbs if verb in all_text.lower())
+        # Cache lowercased strings outside loops to prevent redundant O(N) allocations
+        # Note: all_text is already lowercased by _get_all_text
+        action_verb_count = sum(1 for verb in action_verbs if verb in all_text)
 
         if action_verb_count >= 3:
             details.append(f"✓ Uses action verbs ({action_verb_count} found)")

cli/utils/yaml_parser.py

@@ -182,8 +182,11 @@ def _prioritize_skills(self, skills: Dict[str, list], technologies: list) -> Dic
             for skill in section_skills:
                 skill_name = skill if isinstance(skill, str) else skill.get("name", "")
 
+                # Cache lowercased strings outside loops to prevent redundant O(N) allocations
+                skill_name_lower = skill_name.lower()
+
                 # Check if skill matches any of the technologies
-                if any(tech in skill_name.lower() for tech in tech_lower):
+                if any(tech in skill_name_lower for tech in tech_lower):
                     matching.append(skill)
                 else:
                     non_matching.append(skill)
@@ -215,6 +218,9 @@ def get_experience(self, variant: Optional[str] = None) -> list:
         max_bullets = variant_config.get("max_bullets_per_job", 4)
         emphasize_keywords = variant_config.get("emphasize_keywords", [])
 
+        # Cache lowercased strings outside loops to prevent redundant O(N) allocations
+        emphasize_keywords_lower = [kw.lower() for kw in emphasize_keywords]
+
         filtered_exp = []
         for job in experience:
             if not isinstance(job, dict):
@@ -230,9 +236,12 @@ def get_experience(self, variant: Optional[str] = None) -> list:
                 emphasize_for = bullet.get("emphasize_for", [])
                 text = bullet.get("text", "")
 
+                # Cache lowercased strings outside loops to prevent redundant O(N) allocations
+                text_lower = text.lower()
+
                 # Include if variant is emphasized or keywords match
                 if variant in emphasize_for or any(
-                    kw.lower() in text.lower() for kw in emphasize_keywords
+                    kw in text_lower for kw in emphasize_keywords_lower
                 ):
                     filtered_bullets.append(bullet)