I've used jetpack technologies once, but I wanted to know more about them, and I was worried because there was so much to learn, so I ended up taking this course. It was very helpful because the concepts were explained easily and accurately. In particular, it was good that I could understand the overall flow by applying and refactoring all of the jetpack technologies within one project, rather than learning them in fragments. I think it's also a big advantage that you answer questions quickly. Thank you for the great course :)