By now, we've all written JSON APIs in Rails. But how do you write fast, testable and sane APIs? I'll guide you through the trials of designing and building awesome, scalable APIs. We'll cover rails-api, activemodelserializers, and all the associated goodness that our ecosystem has to offer. I'll speak on the approaches to authentication, how to ensure we remain good REST/HTTP citizens and maybe if I have time I'll share some of my top secret beard grooming tips!