Cache Wars: Make a Slow Page Fast Without Lying to Users

Caching can make a page feel instant, or it can show users the wrong truth at the worst time. In this lab, participants tune a slow dashboard using HTTP caching, server-side caching, client hints, stale-while-revalidate patterns, and careful invalidation.

Each round introduces a realistic constraint: a user updates data, a CDN keeps an old response, a mobile connection drops, or a metric becomes misleading. The goal is not just speed; it is speed with honest freshness guarantees.