People say "No I don't have any past hobby work, never contributed to OSS, and all my professional work is verboten to show" that's not unusual, but it's also not an encouraging sign to me when interviewing.
I just take tabs and rearrange them for personal use. Learn from my mistake and just post whatever to your github, if you fret over its usefulness or purpose you might just never grow your portfolio at all. This was a mistake. You don't have to have some gnu front-page exploratory project.
If you want to shred guitar look up Troy Grady to grok efficient mechanics that won't break your wrist (we type alot for work as well)
Every time I find some open source I would contribute to, what I wanted to implement is already there or is already in the works. I'm not going to change shit just to change it. I'll buy them a coffee tip and leave.
Reasoning about a problem i have (even showing some code) is also a good part of an interview. But it's my side of the field. I just found it's much better to move the interview to the interviewee's side of the turf, because they are more comfortable there.
I know people are vocal about not wanting to do take homes. But if take home is reasonable and used as a talking piece it checks all the boxes for good tool.
I think in reality I had single person that outright refused and of course bunch of people who didn’t bother to deliver - great candidates delivered it the same day, busy great candidates delivered it over the weekend.