Boafo Ticketing

A Turborepo with a NestJS public API, Next.js organizer dashboard, and embeddable Next.js checkout on Prisma, PostgreSQL, Redis, and BullMQ. Correctness is enforced in code: single-writer capacity, server-side price computation, integer-pesewa money, and a mandatory Idempotency-Key on writes — architectural tests fail CI when the rules break. Paystack for card and mobile money, HMAC-signed QR tickets, an offline-capable phone scanner, refunds, transfers, and a sold-out waitlist. Load-tested an on-sale (800 concurrent buyers, 100 tickets, zero oversell) and caught a reverse-proxy rate-limit that would have rejected real buyers after ~8 requests.

• Zero oversell under 800 concurrent buyers for 100 tickets
• Idempotency-Key, integer money, and single-writer capacity enforced by architectural tests
• Paystack card + mobile money, HMAC QR tickets, offline scanner
• OpenAPI product surface with secret vs publishable keys and signed webhooks
• Docker Compose on a single droplet: Caddy TLS, three apps, Postgres, Redis, one-shot migrator