How to organize the work of website layout with API service?

Question

API

There is an API that gives data in the form of json objects for applications and third-party services.
Now you need to develop a site, the server component of which is in the same API scripts. Just different controllers for the site.
You can use some library and load each block of the main page separately through your access point. And then, the api response to convert the data to html and lay it out in the right parts of the site? How do search engines deal with this?
Or is it better for the site to write its own controllers in api, which will return the entire html document (for the main page, for the product catalog, for the list of news)?
Maybe some other approaches are currently being used?

Answer 1

top search engines have long made friends with js/ajax and in general their algorithms have changed: context is nothing, hype is everything. for reinsurance, you can implement Yandex / Google quick pages