I see that you are mostly focused in processes/threads/etc., which is quite an interesting niche (for me, I teach those things in a Operating Systems class). It seems rather risky to pursue a niche as it may be too small! Do you have any tips, like why did you decide to focus on multiprocessing/multithreading? Also, any other Python niches that you think are valuable to focus (for courses, ebooks and tutorials like you do)?
I'm really interested in establishing myself an an online "educator", but I still do not know which kind of topics I should aim to. If I focus on introductory topics there's too much competition. If I focus on a too small niche, I may have no "spectators". Any tips would be greatly welcomed! :)