Full separation of front end and back end

  node.js, question

Today, I went to interview a company. They were separated from each other.
Node.js has built its own API at the front end to call the back end of the service.
The main technology used is sassgulpsea.js.

What do you all think of this front end?

Simple separation of front and back ends can be realized by adding an agent or uniformly using jsonp interface. Disadvantages, can not play the function of the template, the interface can only use ajax form, not friendly to search engines.

The front and rear ends of the module are separated, and the foreground web part runs completely independently, including foreground code and background code. Background services operate independently, providing data and computing services.