Many of the sysadmin jobs I've been applying for want repo links. So when you have a family, and a job where sometimes you have to work 100 hour weeks - and that doesn't let you open source your configuration as code, you have to pick your battles.
And then there's the homework assignments, one job had me submit an architecture design even before I had an interview with the recruiter.
huh - did you send them an bill? That does seem unreasonable - you produced work, you should be compensated... who's to say they aren't just using you for free architecture design?
Practical homework assignments are fairly common and to me seems to be a better sign of a company than those links to coding tests where it takes forever to understand the question and that there are study guides for. I've never had a practical assignment before any interview before though.