Web Performance Skill

Version: 1.0 Stack: Apollo Client/Server + Redis + CloudFront + S3

Performance problems are invisible during development. Local servers are fast. Test data is small. You don't notice the 3MB bundle, the N+1 queries, or the full-table scan until real users on real connections with real data report that the page takes 8 seconds to load. By then, fixing it requires rearchitecting the caching layer, splitting the bundle, and rewriting queries — all at once, under pressure.

Performance patterns applied from the start are cheap. Performance fixes applied after launch are expensive. These rules are the cheap version.

Core Principles

1. Measure First — Profile before optimizing. Don't guess.
2. Cache at Every Layer — CDN → API → Database → In-Memory.
3. Minimize Payload — Send only what's needed.
4. Defer Non-Critical — Load critical path first, everything else later.
5. Perceived Performance — Optimistic UI makes things feel faster.