Caldav with decsync and syncthing to synchronize across devices
~/scratch.txt in my text editor of choice opened automatically on startup with a keyboard shortcut to show/hide it
And GitHub issues for collaboration
Teams boards (shared to dos)
Planner (personal lists)
Writing it down on a sticky note (priority)
Servicetitan Task Management (ugh, not a huge fan but required).
Monday (shared and I really like this one but it’s only for a particular dept’s needs).
Taskwarrior, tried lots and lots of ones but always come back to Taskwarrior. It just works the way my brain does, and has tons of features that I actually use because they are intuitive and easy to remember how to.