caching-queues-cache-strategy-layerslisted

# Layer caching with explicit invalidation > Decide what caches where (CDN, app, Redis) and how entries die so staleness stays bounded. **Track:** ⚙️ Backend Engineering · **Domain:** Caching & Queues · **Level:** intermediate · **~35 min** **Who this is for:** Backend Engineers, API Developers, Platform Engineers, Full-Stack Developers ## When to Use This Skill Decide what caches where (CDN, app, Redis) and how entries die so staleness stays bounded. Use it whenever a matching task appears in conversation — the agent loads these instructions on demand. ## Steps 1. Classify data: immutable (cache forever), mutable-TTL, never-cache (money) 2. Cache at CDN for anonymous GETs with stale-while-revalidate 3. Memoize expensive computed objects in-process with short TTL 4. Use Redis for shared cross-instance state; set TTLs on everything 5. Invalidate by key pattern on write events, not manual flushes 6. Monitor hit-rate per layer; below 60% means wrong layer or wrong keys ## Common Pitfalls - Caching authenticated responses at shared CDN edge - Thundering herd on expiry without jitter or locks ## Commands **Install with skills CLI** ```bash npx skills add aniruddhaadak80/skills --skill caching-queues-cache-strategy-layers ``` **Install globally** ```bash npx skills add aniruddhaadak80/skills --skill caching-queues-cache-strategy-layers -g ``` --- Part of [aniruddhaadak80/skills](https://github.com/aniruddhaadak80/skills) · Browse all at https://skills.sh/aniruddhaadak