Every business app you use—whether it’s a simple to-do list or a sprawling enterprise system—once existed only as an idea in someone’s head. The journey from that idea to a tool people rely on every day follows a careful process. In this chapter, we’ll walk through the methods and mindsets that teams use to design, build, and launch information systems, and we’ll see why picking the right approach can make the difference between a smooth success and an expensive mess.