This video is part of a series in which we will create an activity visualizer for subreddits in C#. In this video we will update our code, so it becomes testable. We do this by replacing tightly coupled classes with interfaces through dependency injection. Afterwards we create unit tests for our classes. The code that is written in this video is pushed to the part-3 branch of the GitHub repository that can be found at this url: https://github.com/CodeAlongWithRon/S…. In the next video we will add a new feature to the application. We will fetch the amount of posts and comments for a subreddit in the last 24 hours.