Let's face it - the more successful a product is, the more complex it becomes. New features are pulled into the backlog, bugs pile up like candy on Halloween and deadlines move from "We need it Tomorrow" to "It had to be done last week!". As a result teams grow, new ones emerge and a once small and simple app overpasses the dex limit and requires 300 seconds for a cold build (if you're lucky, of course). At XING we value quality, but we also require speed and a continues delivery that should never stop. With seven+ teams contributing to the main app the risk of breaking the stability of the project is even higher. Thus a clean and straight forward architecture is key for a successful rollout and our QAs sanity. This talk is about our journey from a one-block app (with a twisted maze of legacy code on top), to a multi modular and sustainable project consisting of small semi-autonomous components that assemble into our flagship app. Almost like a jigsaw puzzle.