This is a tale of a large, feature-rich and Backbone-driven single-page app. A mobile banking app, possibly Norway's largest and most complex single-page app. The codebase has grown to over 100k lines of js. At scale, any flaws in your frontend architecture has transformed into a nasty monster that will bite you in the ass at every opportunity. Thus - our repo is a monster zoo by now. We've managed to reduce the complexity in our app by utilizing React as our view layer. The functional and declarative way of programming is our bug vaccine, and reusable components is our consistency pill. The coexistence of React and Backbone is not entirely straightforward, but has helped us tremendously in dealing with our big state machine. This journey has taught us some valuable lessons. This is the story of how we used React to tame the single-page beast.