CORS Caching and Performance Optimization
CORS performance usually gets treated like background noise until your frontend starts making hundreds of API calls and every second request triggers an OPTIONS preflight. Then it becomes very obvious: bad CORS config can waste latency, server CPU, and CDN cache efficiency. I’ve seen teams obsess over query performance while every browser quietly burns extra round trips on preflights they could have avoided. This guide is the practical version: what gets cached, what does not, and what headers to set when you want cross-origin requests to be fast without turning your policy into mush. ...