The Catalog.Domain project now contains the core logic of the entire application. Although the logic implemented in the Domain project is still quite simple, later on in this book, it will become more complex.
The topics covered in this chapter included some of the concepts related to the domain logic implementation of a web service: how to implement the service and the mapping classes, how to implement the request validation process using a fluent approach, and finally, how to test our code using some unit testing techniques.
The next chapter will look into all the HTTP parts of the application. Furthermore, we will focus on the Catalog.API project, and how to put together the data access, the service, and the API layers.
