I vibe coded a 3D city with 21,000 lines in 4 days - every GitHub dev is a building

Built entirely with Claude. 21,000 lines of Next.js + Three.js + React Three Fiber + Supabase + Stripe. The result: a 3D pixel art city where every GitHub developer is a building. You can fly through it, unlock achievements, compete on leaderboards, and customize your building with items like hologram rings and neon auras. It went viral in Brazil (96k views in 24h). People started buying ad space inside the 3D city. Revenue on day 1 from an open source project. Some technical challenges the AI handled well: * Instanced rendering for 500+ buildings at 60fps * LOD system with texture atlasing * Stripe checkout integration * Supabase auth + RLS policies * Spiral city layout algorithm Where I had to step in: * Architecture decisions (what to build, in what order) * UX flow and feature prioritization * Visual design direction * Performance debugging Try it: [https://thegitcity.com](https://thegitcity.com) Source:…