Note: A newer, updated edition of this book is available (ISBN 979-8-9985862-0-0)."Hexagonal Architecture Explained How the Ports & Adapters architecture simplifies your life, and how to implement it Updated 1st Edition". Please prefer that one to this "Preview Edition". "Looking at the screen of my laptop, I realized that it was full of code that didn't let me understand what it did regarding business logic. From that moment I began to search until I discovered the architecture that decouples the business logic from the frameworks: Hexagonal Architecture, more correctly called Ports & Adapters. From that moment until now, I haven't stopped reading and learning about this pattern." Recommended by giants like Netflix and Amazon, the Hexagonal or Ports & Adapters architecture simplifies testing, protects against business logic leakage, supports changing technologies in long-running system, and lets you apply Domain Driven Design. In this definitive book on the subject, pattern author Dr. Alistair Cockburn and Juan Manuel Garrido de Paz lay bare all of the intricacies of the pattern, providing sample code and answering your many frequently asked questions.