How about unidirectional data flow in an architecture where views and presenters don’t know about each other? While growing up to 40+ engineers and 600+ modules, Cash App managed to control the complexity of its product. Views can be written in either Kotlin or XML; presenters with either Rx, Coroutines, or Compose; no problem. We test views on the JVM and we don’t need to define fake presenters either. Writing new screens is delightful and we’ll see how we made it possible by: - Looking at the foundations of the architecture: our internal navigation library which allows clear modularity, - Checking how it can adapt to presenters using different technologies, - Explaining how views are defined and tested, - Seeing how everything is glued together from a bird’s-eye view of the app. Growing your app and team doesn’t imply more pain nor more complexity. Attendees will gain a sound understanding about how we achieved it.