What the cache?!
".. and then cache the hell out of it!" This is usually how the talk ends when it comes to rails performance tips, but in reality it is where the fun starts. This talk goes way beyond Rails.cache, it explores layered caches, discusses the CPU cost of marshaling, the latency even Memcache adds and how to dodge the unavoidable stampedes that invalidating your caches will cause. This is the tale of how to survive half a billion requests per day with Rails and MySQL (hint: don't query it).