From a more academic approach [1], if you care about efficient concurrency and no context switching between frontend-backend, the node.js platform is an excellent choice.

Figure: http://imgur.com/NnQ9M5v

[1] http://link.springer.com/article/10.1007/s00607-014-0394-9 "Is Node.js a viable option for building modern web applications? A performance evaluation study"