Typescript is awesome! What you demonstrate is very much in use in Typescript coded Frameworks or Libraries! If you have energy to go on with your series, it would be very interesting to see you explaining parts of a Typescript coded Library! Sample: NgRx, redux style Typescript coded Library with lots of Mapped and Utility Types: github.com/ngrx But anyways: Great Series on Advanced Types in Typescript with good samples - Thank's a lot for publishing!! ^_^