Sheares App v3
A real-time community app for 500+ hall residents.
A hall-wide noticeboard, room-booking, and event app I've maintained since freshman year. v3 swapped the old polling backend for a serverless WebSocket fan-out on AWS and cut p95 notification latency from 9s to 280ms.
- WebSocket fan-out via API Gateway + Lambda + DynamoDB streams.
- Replaced WhatsApp announcements; spam down ~70%, notice retention up ~3×.
- Deploys in one terraform apply; CI/CD via GitHub Actions + OIDC.