You built your system, you deployed it, you rolled it up in production, but it’s just the beginning. The life of your system just started. It will grow, evolve, and wake you up in the middle of the night. Usually, at this point you start thinking about fault tolerance and error handling. In this talk you will learn practical recipes (code and design patterns) to build fault-tolerant, scalable systems using open source tools; and understand the role of product decisions in building fault-tolerant software and the importance of a proper communication culture.