Denis Žoljom, a WordPress core contributor and plugin author, shares his experience creating a decoupled (“headless”) WordPress site. Denis covers the advantages and disadvantages of the decoupled approach when you are setting up a site and using the WordPress REST API. He also shows how to build a plugin that fetches the JSON data from your WordPress site much faster without using the REST API.
Although it's usually more work, a WordPress-powered backend is an idea I find fascinating. It plays to WordPress's strengths while also addressing performance. While headless WordPress is not the solution for many use-cases and probably not worth the effort currently for a lot of scenarios, I expect to see more articles on it as developers experiment and streamline some of the processes involved.