Where we started
A single Node.js server behind an Nginx reverse proxy. It worked until it didn't — the first Black Friday showed us exactly where the ceiling was.
The caching layer
Redis for session state, Cloudflare for edge caching, and a custom invalidation pipeline that could flush specific cache keys in under 50ms globally.
The database strategy
Read replicas for the hot path, write-through cache for mutations, and a separate analytics pipeline that never touches the production database.
engineering