Implement a headless/decoupled Drupal design to build easily maintainable web applications. This book begins by showing you CMS workflows and best practices to give you the basics you need for working with decoupled Drupal. As part of this process, Decoupling Drupal reveals the advantages of using content management systems and explains that decoupled Drupal is the answer to various problems faced in creating and maintaining enterprise applications.
Decoupling Drupal will show you how administering Drupal monolithically to design web applications can be a challenge. You’ll see how the maintainability of your application reduces exponentially over the years. In contrast, a decoupled design enables an easy handshake between the front-end and back-end applications, meaning you can implement services in a short amount of time and scale them quickly. 
The final part of the book covers the impact of decoupling on functional and non-functional requirements and the use of Drupal 8 modules to address the requirements of decoupling. This involves solving the problems that occur at different stages of CMS evolution in an organization.