I started maybe four years ago and I wrote it during a period of a year and a half. This is a 17 part very detailed Flask tutorial. It's starting to age a little bit. So yeah, that basically covers a bunch of areas. For example, I'm really proud that I have very good coverage for internationalization. Not very many people talk about. You can learn how to do that with Flask Ajax,. which is more common now with single page apps. That was basically a source of not only a way to teach what I learned, but also to, he mean the myself to learn because it pushed me to learn more things.