Do you want code that's maintainable, extensible, and easily testable? If so, then C# interfaces are here to help. In this course, we’ll take a look at how we can use interfaces effectively in our code. We'll start at the beginning ("What are interfaces?") and then explore why we want to use them. Along the way we'll create and implement own interfaces, see how to explicitly implement interfaces, and take a look at dynamic loading, unit testing, and dependency injection. All of which is made possible with interfaces.