Author here. You are right, we missed those, most likely because we were focussing on MVC Frameworks. Anyway, a quick search in our startup jobs database show

Author here. You are right, we missed those, most likely because we were focussing on MVC Frameworks. Anyway, a quick search in our startup jobs database shows that in Barcelona there are 8 open positions for Ember.js, 4 for Backbone, 1 for flask, and none for Play Framework. AngularJS was not added to the list because it's a platform, not a framework.