The best way to stay up to date on all the possibilities in Microsoft 365 / SharePoint development is to dive in and give it a try.

When I come across something I find interesting, useful or noteworthy for any other reason, I will try to make a note of it here. Hopefully it can be of use to others as well!

(Content gets outdated quite quickly as time goes by, and many of the problems/findings discussed here might not be relevant any more)