Master-Class: Caching — What Every Software Engineer Actually Needs to Know

Skip the theory rabbit holes. This is the caching knowledge that shows up in system design interviews, code reviews, and the 2 AM production incidents nobody warned you about. Table of Contents Why Caching — The 30-Second Version Where Do You Actually Cache? Cache-Aside — The Pattern You'll Use 80% of the Time Write Strategies — The Other Side of the Coin Eviction Policies — LRU, LFU, and When It Matters TTL — Getting Expiry Right Cache Invalidation — The Hard Problem Cache Stampede — The Failur