I Built an AI That Finds Your Bugs and Rewrites Your Code to Fix Them.

How I built CodeLens — a Groq-powered code review tool that detects SQL injection, memory leaks, and O(n²) algorithms, then rewrites your entire file with all issues resolved. Full breakdown of the architecture, prompt engineering tricks, and the LLM hallucination problem I had to solve. Every developer has shipped a bug they should have caught. Not because they were careless. Because code review is expensive. You're scanning hundreds of lines for subtle patterns: a missing conn.close() , an f-string wired directly into a SQL query, a nested loop that looks innocent at n = 10 but detonates at n = 10,000 . I wanted to build a tool that never gets tired, never misses a pattern, and can tell you exactly what will go wrong in production — before you push. That's CodeLens . What It Does Paste any code. In seconds you get: A health score (0–100) with an animated gauge Every vulnerability categorized by severity: CRITICAL , WARNING , INFO Exact line numbers, descriptions, fix suggestions, and