I assume the point of these tutorials is not to show experts how to progress from the state of the art, but to show beginners how to get there. There are a few

I assume the point of these tutorials is not to show experts how to progress from the state of the art, but to show beginners how to get there. There are a few tutorials like this (build your own text editor, operating system, etc) and I think they are a great idea if done well.