As part of the Finance Engineering team at Groupon, we pay merchants in dozens of countries. Over the last four years, our Rails service has processed lots of dollars (and other currencies) and seamlessly recovered from millions of blips, outages, and other errors. This is a real world talk that is more than just "solved challenge foo with method bar." It's about how our team looks at our problems, our code and ourselves. We will look at how we use Rails to help create a team that owns their culture, manages their operational risk, and moves fast.