As the final chapter of this book, I want to present a case study in unit testing. This chapter bridges theory and practice by demonstrating real-world testing applications through a simple example. It highlights common pitfalls such as poor architecture and coding practices while showcasing best practices for writing maintainable and effective tests. By comparing bad and good approaches, you'll observe progressive improvements and gain a deeper understanding of proper coding, architecture, and unit testing. To illustrate these concepts, I’ll use a small ASP.NET Core Web API. In this chapter, I will show you