Software developer. Self-hoster.
I love wikis for collaboration or for a more formal notebook.

Most useful thing to have with your scraps of information? TAGS.
Don’t worry about hierarchy or graphs. TAG it and move on.

For note taking have used (Windows OS):
Tomboy
OneNote

New notes going to Silverbullet.md!

Would go with Obsidian if it weren’t for Silverbullet. People like to show a graph, but I find that fluff and not really useful.

Have tried:
Stashpad (going EOL)
Logseq
TiddlyWiki