We used Scala, AngularJS and PostgreSQL. Actually except AngularJS we are really really happy. Everything is fast and the development speed is ridicoulus, especially calculations and performing operations on big lists are extremly good in Scala. Actually we are probably introducing Redis (actually we use Akka-Cluster for PubSub) however we think that with Redis we can even be faster and Cache our stuff better.

For our JavaScript stack we will also look into ScalaJS and/or Vue.JS, React and Ember, but at the end we probably handroll our own at this stage, since our feature set is really different from what these provide (we don't need any mobile stuff, really...), at the moment we have zero mobile clients and we looking to build an app for a small inventory service, but thats all.