Built a World Cup planner and simulator app solo with Cursor + Claude
Been building a World Cup simulator and planning app using Cursor + Claude for the past few months as a hobby project. Nights and weekends. I was the architect. Claude was my chief marketing officer, UX designer, data scientists, and overall advisor, and Cursor was my engineering team. I used to code years ago and have built production systems on AWS – but I'm rusty so I decided to try to use AI.
Stack: React/TypeScript/Vite/Tailwind frontend, Capacitor for iOS (Android soon), Python/FastAPI on AWS Lambda + API Gateway + DynamoDB/S3, AWS CDK + AppConfig for remote runtime config, Playwright for server-rendered share images, RevenueCat for IAP, Sentry/PostHog for observability.
What I built:
- 10,000 Monte Carlo simulations across 104 matches
- ELO rankings engine
- What-If engine that recalculates the entire bracket instantly on device
- Tiebreaker explainer for the new 48-team format
- Trip planning
The hardest parts were keeping all the World Cup logic straight and actually thinking rather just letting AI doing its thing, tracking down bugs, the share card functionality, and finding a point to stop adding functionality.
The app is live: worldsoccerplanner.com. Happy to answer questions about the stack or the workflow.
Also, if anyone has ideas on how to get this in front of soccer fans, I'm all ears.