Here's the three answers you will get when try looking deeply for it:
1) Quick prototyping old-school: Ruby with Rails or Python with Django
2) Asynchronous Single Page App: Node.js using either something like Meteor (fullstack) or combining something like Express(backend) with Angular/Ember
3) You already have big clients, you need 'scaling' immediately: Java or Scala with one of their frameworks.
Comments
Here's the three answers you will get when try looking deeply for it:
1) Quick prototyping old-school: Ruby with Rails or Python with Django
2) Asynchronous Single Page App: Node.js using either something like Meteor (fullstack) or combining something like Express(backend) with Angular/Ember
3) You already have big clients, you need 'scaling' immediately: Java or Scala with one of their frameworks.