File caching, Memcache, Squid, Varnish and ESI have become common tools in arsenal of those pushing their application to millions of users a day. However, these strategies have not been without their drawbacks. Cache invalidation, and immature implementations within Ruby have hampered the support of these in the real world. Examining the current crop of tools and their limitations can shed light on both the problems and the solutions. Whether you're serving a relatively small website or are managing a whole farm of servers, quick responses can make the difference between joy and user frustration. This talk will discuss: "Current caching strategies and their strengths and weaknesses", "Invalidation performance and the "dog-pile" effect" and "Real live working code - Plenty of benchmarks". We will take a sample application through these various caching strategies, paying attention to ease of implementation and performance along the way. By employing EventMachine, Tokyo Cabinet, Tokyo Dystopia, Rack and some sweet syntactic sugar, we will find the easy, golden path for web performance.