Refactoring code by implementing SOLID, KISS, DRY and YAGNI principles
You are asked to refactor the UserService class and more specifically its AddUser method.
Assume that the code is sound in terms of business logic and only focus on applying clean code principles. Keep in mind acronyms such as SOLID, KISS, DRY and YAGNI.
Try to keep this exercise below 2 hours. If you still have things you can improve after the 2 hour mark, please write them down and we will take them into account.
The Program.cs class in the LegacyApp.Consumer shall NOT CHANGE AT ALL. This includes using statements. Any sort of change in that class will result in you instantly failing this test.
You can change anything in the LegacyApp project, but assume that this codebase is part of a greater system, and any non-backwards compatible change will break the system.