Confidence Check Pre-implementation validation framework. Never code at < 90% confidence. Why This Matters Wrong-direction work costs 5K-50K tokens to undo. A 2-minute confidence check saves hours of rework. The 90% Rule Before implementing ANY significant change: Confidence Checklist 1. Duplicate Check (20 points) - [ ] Searched codebase for existing solution - [ ] Checked if similar pattern exists elsewhere - [ ] Verified not reinventing existing functionality 2. Architecture Alignment (20 points) - [ ] Understand where this fits in the system - [ ] Know which files/modules are affected - […