Any server-side language is fine because the problem isn't about learning the language. The problem is the framework (and convention) that is being run on top o

Any server-side language is fine because the problem isn't about learning the language. The problem is the framework (and convention) that is being run on top of the language. For instance, I know Java enough to read the code and write something useful. But say you jump around projects that make use of different web servers or different server-side frameworks, that's what causes the overhead. Anyways, if you're aiming for a mid to high level company, I suggest Java (Spring), C# or PHP (Laravel, Drupal) as the enterprise will look for stable, long-term frameworks. If you're aiming at start-ups where things are hype-driven and fast-moving, go Ruby (Rails), Node (express) or Python (Django). Same goes for the front-end. If you want stable and long-term, go for Ember or Angular or Backbone. If you want hype-driven and fast-moving, go for React and it's clones.