Now, the other app my team works on is built with Backbone/Marionette. We've introduced React and Redux to it, and are progressively refactoring over time. It works, although we've got some rather ugly code in several places (some data is in Backbone collections, other data is in Redux, and occasionally some bits of data are mirrored in both places).

I wrote about some of the techniques we're using to integrate them here: https://blog.isquaredsoftware.com/2017/07/react-redux-backbo...