This book, designed for beginners, will introduce you to the field of agile software development with C#. There are many books on C# and just as many, if not more, on agile, but few teach a programming language and software development methodology in conjunction. Agile blurs the lines between the roles of analyst, designer, programmer, and tester. Therefore, when you learn agile, you will learn to analyze, design, develop, and test. By combining C# and agile in one book, you will be able to experience all roles through a single journey. At the end of the book, you will be given several tiny C# projects to work on following agile philosophy. Working through these projects with four or five other readers (e.g., as in a college setting) would further benefit your understanding. This book is not a reference, so content will be kept at a minimum. This book is also not an in-depth cover of any specific topic, instead designed to cater to beginners. Readers may always research the web for further details. This book requires you to type all code. We don’t provide sample code downloads. Though we understand your time is valuable, we believe hands-on practice is the best way to learn. Throughout the book, you will be given plenty of exercises under the titles of Programming Challenge and Test Your Understanding . We strongly encourage you to try all exercises as you work through the book. This third edition uses Visual Studio 2022 Community as the development environment. Last but not least, we thank Dr. Youlong Zhuang for reviewing this third edition and providing valuable suggestions.