Caching 101
A cache is a copy of data kept somewhere faster to access, so a repeat request skips the expensive path entirely. The tradeoff: staleness, always.
Caching Strategies
Cache-aside, write-through, write-behind, read-through — each strategy answers differently who populates the cache and when a write updates it.
Cache Eviction Policies
LRU, LFU, and FIFO decide what leaves a full cache, and the wrong policy for your access pattern quietly tanks your hit rate. Plus: cache stampede.
Distributed Caching
A distributed cache shards itself across nodes via consistent hashing, spreading capacity and risk, but hot keys can still overwhelm a single node.
CDN
A CDN caches content geographically close to users, sidestepping the physical speed-of-light floor on latency that no server optimization can fix.