Caching 101: The Ultimate Guide to Caching — From Basics to Production-Grade Strategies

Caching 101: The Ultimate Guide to Caching "There are only two hard things in Computer Science: cache invalidation and naming things." — Phil Karlton If you've ever wondered why some apps feel instant while others make you stare at a spinner — the answer is usually caching . It's one of the most powerful performance tools in a developer's toolkit, and one of the most misunderstood. This guide covers everything — from what caching is and why it matters, to production-grade strategies used by Netflix, Twitter, and Facebook. Whether you're building a side project or designing systems at scale, this is your complete reference . Table of Contents What Is Caching and Why It Matters The Latency Numbers Every Developer Should Know Types of Caching Caching Strategies Cache Eviction Policies Where to Cache HTTP Caching Deep Dive Redis Caching Patterns Cache Invalidation — The Hard Problem Cache Stampede / Thundering Herd Real-World Examples Decision Framework Common Mistakes What Is Caching and