We are in the middle of a change of the stack on the front end. So we used Backbone.js with Marionette. Then we also created our own implementation of a Flux kind of flow. We call it eb-flux. We have worked with Marionette for a long time. Then at some point we start evolving and end up having a kind of Redux.js-style architecture, but with Marionette.
But then maybe one and a half years ago, we started moving into React and that's why we created the Eventbrite design system. It's a really nice project that probably could be open sourced. It's a library of components for our React components.
With the help of that library, we are building our new stack with React and sometimes Redux when it's necessary.