Now that decoupled Drupal has permeated the Drupal community, even to the furthest extremes, articles (including my own) introducing concepts and how-to tutorials describing how you can build your first decoupled Drupal architecture are ubiquitous. As a matter of fact, decoupled Drupal now also has a book on the subject as well as an annual conference dedicated to the topic. Particularly with the JSON:API module in Drupal core as of 8.7.0, decoupled Drupal out of the box has never been easier.