With the Varnish caching proxy you can make websites blazingly fast. The basics are quite simple once you understand how cache handling in HTTP works. For starters, we will look into HTTP and Varnish configuration. The main course is going to be test-driven cache invalidation and the cache tagging strategy. For desserts, there will be an introduction to Edge Side Includes (ESI). All of this will be liberally sprinkled with examples from the FOSHttpCache library and some ideas from the FOSHttpCacheBundle for Symfony2.