I’ve learned how to build distributed systems the hard way; I’ve failed, and failed again. I’ve made many of the common mistakes and tried a few other things that turned out to be a disappointment. You shouldn't have to make those mistakes too. In this talk I'll tell the story of how I built a real time advertising analytics platform that tracks and reports on millions of impressions every day, and all the things I did wrong before I got it to work. I’ll also tell you what I did right, and the choices I don’t regret.