How to separate front and back ends in traditional web development, or is it necessary to separate front and back ends

  node.js, question

The separation desired here is:

  1. The front end is independently developed and released.
  2. The necessary pages are rendered on the server side.
  3. Browser compatible with regular versions, e.g. ie8 plus

I would like to know if there is a good plan or if it is necessary to do so.

The separation of the front and rear ends is not as complicated as you think.
Write the interface in the background
The front desk realizes the page according to the interface, isn’t it finished?
As for compatibility, according to product requirements.
The separation between the front and the back is not as high as it should be. It’s just a matter of improving the efficiency at both ends.