This book is for Swift developers who have at least an introductory knowledge of the Swift programming language, who want to learn and implement protocol-oriented programming in their real-world applications. It is also for developers who not only want to understand protocol-oriented programming, but also want to fully understand the different components of the programming paradigm. This book is written for developers who learn best by looking at and working with code, because every concept covered in the book is backed by example code written to give the reader a solid understanding of the current topic and to demonstrate how to properly implement it.