Built real-time engagement system enabling live polls, quizzes, and Q&A during events with sub-300ms latency. Integrated WebSocket and Redis Pub/Sub for real-time vote updates and analytics, reducing latency by 150ms. Implemented role-based access control with password-protected events and expiring session links.

Built a streaming platform for 500,000+ movies, TV shows, and anime using TMDb API with a Watch Party feature — real-time video/audio via LiveKit WebRTC with screen sharing and host sync via Data Channels. Reduced TMDb API calls by 90% via read-through caching on Upstash Redis with TTL-based invalidation, achieving sub-10ms cache hits. Implemented type-safe bookmarks and watch history via tRPC mutations persisted to Neon Serverless Postgres with Prisma ORM. Designed a 7-provider fallback chain with server-side ping probing ensuring uninterrupted playback.

Built a Redis-compatible in-memory key-value store from scratch in Go, implementing the RESP2 wire protocol over raw TCP with zero external dependencies. Designed concurrent client handling via goroutines with per-type sync.RWMutex, supporting 4 data types (String, Hash, List, Set) across 42 commands. Implemented TTL expiry via a min-heap, AOF persistence with startup replay, and Pub/Sub fan-out using Go channels.