Hands-On Labs
Real caches, real configs, a real terminal. Each lab gives you a private stack you can break and rebuild.
Module 2 · Understanding Cache
Debug a Two-Tier Cache
An nginx edge sits in front of a Varnish cache in front of a Flask origin. Every request reaches the origin. Find out why, and make the edge actually cache.
40 min · 200 pts
Publish a Fix Without Waiting for the TTL
A page went out with a wrong price and it is cached for an hour. You cannot wait an hour. Build a purge mechanism — and make sure it cannot be used by anyone who finds the URL.
45 min · 250 pts
Module 3 · Headers & Configuration
The Cache That Serves the Wrong Thing
The edge caches beautifully and serves English content to Dutch visitors. Fix the cache key without destroying the hit rate.
45 min · 250 pts
Module 6 · Advanced Topics
Keep Serving When the Origin Dies
The origin can be switched off at will. Right now that means 502s for every visitor. Configure the edge to keep serving stale content through the outage.
35 min · 200 pts