The banking sector is well known for using large, sometimes monolithic, legacy systems. Now, banks find themselves having to catch up with rapid advancements in software development that call for new service-oriented computing paradigms. Unfortunately, this task is nontrivial and often requires huge projects that are costly, time consuming, and risky. The safe choice for a development methodology is a process framework such as the Rational Unified Process (RUP), which is customizable enough to fit any project. However, customizing RUP isn't trivial, so it's often used in its full-blown out-of-the-box form, which entails significant sacrifices of time, cost, and flexibility. The Agile Unified Process (AUP)-a hybrid approach designed by Scott Ambler combining RUP with agile methods to a successful project in the banking sector. The project achieved on-time delivery within budget, integrating heavy legacy back-end application systems with newly reengineered client user-interface applications on a modern service-oriented architecture (SOA) platform.