Caching Deep Dive for System Design Interviews

Caching appears in virtually every system design interview. Whether you are designing a social media feed, e-commerce platform, or URL shortener, caching is essential for achieving low latency and high throughput.

Interviewers expect you to know not just that caching helps, but how to choose the right caching strategy, where to place caches, how to handle invalidation, and what trade-offs each decision involves.

This chapter provides a deep understanding of caching for system design interviews. We will explore caching fundamentals, different caching layers, strategies for reads and writes, eviction policies, distributed caching with Redis and Memcached, cache consistency challenges, and common interview scenarios.