"Head First Design Patterns: Building Extensible and Maintainable Object-Oriented" is a textbook authored by Elisabeth Robson and Eric Freeman, focusing on the subject areas of programming languages, computer science, and object-oriented programming. Published in 2021, this trade paperback explores the concepts of design patterns and their application in creating flexible and long-lasting code. Written in English, this book serves as a valuable resource for those looking to enhance their programming skills and understand how to build extensible and maintainable software.