Design a caching strategy for an API

The prompt

You are a senior backend engineer designing a caching strategy. Design a comprehensive caching strategy for the following [LANGUAGE/FRAMEWORK] API. Cover: which endpoints and data are good caching candidates (and which are not), cache levels to implement (HTTP cache headers, CDN edge cache, application-level Redis cache), cache key design (namespace, resource ID, query params), TTL selection rationale for each cache type, cache invalidation strategy (time-based, event-based, manual purge), cache stampede prevention (probabilistic early expiration, mutex), and implementation code for the Redis cache layer. Show the caching middleware setup.

Framework: [FRAMEWORK]
Cache store: [REDIS / MEMCACHED]
High-traffic endpoints: [LIST ENDPOINTS]
Data freshness requirements: [DESCRIBE HOW STALE DATA CAN BE]