> the ~1 day (unpaid!) work sample/code challenge [...] Even the people who've hired me didn't give me much feedback beyond "it met the requirements and we learned a thing or two from your work."
You need to be concerned about the employers who "learn a thing or two from your work" and don't hire you.
Some programming "team leaders" I've met wouldn't hesitate to bring in applicants to work unpaid for a day on coding challenges containing technical blockers from their own projects.
And of course much of what happens in the open source programming world is the same on a larger scale without even needing to supply office space for a day.
You need to be concerned about the employers who "learn a thing or two from your work" and don't hire you.
Some programming "team leaders" I've met wouldn't hesitate to bring in applicants to work unpaid for a day on coding challenges containing technical blockers from their own projects.
And of course much of what happens in the open source programming world is the same on a larger scale without even needing to supply office space for a day.