Caching Strategies with Claude Code: Redis Patterns and Cache Invalidation

Caching is easy to get wrong. Cache too aggressively and you serve stale data. Cache too little and you get no benefit. Claude Code can implement caching patterns correctly — with the right CLAUDE.md configuration. CLAUDE.md for Caching ## Caching Rules ### What to Cache - Master data (user roles, config, feature flags): TTL 5min - Expensive computations (aggregations, reports): TTL 15min - User sessions: TTL = session expiry - API responses from external services: TTL 1min ### What NOT to Cache - User-specific transactional data (orders, payments in flight) - Real-time data (stock prices, live notifications) - Anything that must be consistent immediately after write ### Cache Keys - Format: `{service}:{entity}:{id}:{version}` or `{service}:{entity}:list:{filter_hash}` - Examples: `user:profile:123` , `product:list:abc123` , `config:features:v1` - Never use raw user input in cache keys (injection risk) ### Invalidation Strategy - Write-through: update cache on every write (for consiste