cdn

Understand where caches live, how cache-aside, read-through, write-through, and write-back differ, how to choose eviction policies, and how to prevent cache stampedes — with hit ratio math and a concrete cache-aside code snippet.

Why your assets should never come from your origin. How a CDN's edge cache, geographic routing, and invalidation actually work, plus the cases where a CDN doesn't help (or quietly hurts).