Edge Caching Strategies to Cut Latency and Cost

Why edge caching changes the latency equation Cache-Control and TTL patterns to make behavior predictable Surrogate keys and targeted invalidation workflows Measuring cache ROI and controlling cost A practical checklist and runbook for edge cache policies Sources Edge caching is the fastest, cheapest lever you have to cut user-visible latency; misconfigured caching is the stealthiest source of both poor UX and runaway origin cost. I draw on running high-traffic edge platforms to give you exact patterns—Cache-Control composition, sensible TTLs, stale-while-revalidate, and surrogate-key invalidation—that move latency off the critical path and shrink bills. You see this in audits: spikes in P95/P99 latency that coincide with cache misses, dashboards that show rising origin RPS, teams purging entire CDNs after content updates, and exploding numbers of cache keys because headers and query strings vary unpredictably. Those symptoms are operational signals: cache exists, but it isn’t shaping