BikeShare
May 2026 – Present- Built a full-stack peer-to-peer rental marketplace with JWT auth and role-based access across 3 user roles, 12 pages, and ~30 REST endpoints, letting students list, search, and rent bikes, scooters, and skateboards.
- Implemented indexed geospatial radius search in PostGIS over a GiST spatial index, with radius, price, type, rating, and availability filters.
- Engineered a privacy layer that exposes only approximate pickup locations until a booking is accepted.
- Engineered a booking engine that prevents double-booking under concurrency, combining interval-overlap checks with pessimistic row-level locking to serialize simultaneous acceptances, enforced by a state machine and integration tests.
- FastAPI
- PostgreSQL/PostGIS
- React
- TypeScript
- SQLAlchemy