Context A product catalog endpoint performs an expensive database query on every request, resulting in slow response times during peak traffic. The Problem There is no caching layer, so identical read requests repeatedly hit the database even when the data has not changed. Constraints Cache the query result in Redis with a TTL of 60 seconds. Return the cached value on subsequent requests within the TTL window. Invalidate the cache entry when a product is updated or deleted. Use a consistent cache key naming convention. Expected Deliverable An Express endpoint with Redis-based response caching, TTL expiry, and explicit cache invalidation on write operations.