PlayZeet: building a peer-to-peer sports-betting platform end to end

The problem

PlayZeet needed a peer-to-peer, group, and novelty sports-betting product that could safely handle real money from day one — no staging period, no synthetic liquidity. That meant the bet-matching logic, payout math, and settlement pipeline all had to be correct under real financial risk, not just functionally complete.

What I built

As founding engineer I owned the platform end to end:

• A bet-matching engine handling lay bets, brave-take applicability, and currency-equivalence logic between counterparties.
• A pari-mutuel payout formula for group bets, plus a scheduled settlement job that closes out markets on a timer.
• JWT session management with multi-layer expiry detection to keep long-lived sessions safe without forcing re-logins mid-bet.
• A Puppeteer-based SSR/SEO layer in front of the React SPA so betting markets are indexable and shareable.
• Crypto (NOWPayments) and card (Flutterwave) deposit integrations, reconciled through BullMQ background jobs against provider webhooks.

Stack decisions

NestJS + Prisma + PostgreSQL for the core API, Redis and BullMQ for queues and settlement scheduling, Socket.IO for live odds and market updates on the client.

Outcome

The platform is live in production at playzeet.com, processing real-money bets across crypto and card deposit rails.