Crowdsourcing

Building Rally: A Live, Crowdsourced Court Map That Stays Honest

How I built Rally, a gamified, crowdsourced map that shows which tennis, pickleball, badminton, and soccer courts are free right now, using an Expo and React Native app on Supabase Postgres with PostGIS spatial queries, GPS proof-of-presence check-ins, and server-side-only scoring so the crowdsourced map stays trustworthy.