Hmm, it seems like you are looking at how you should triage an applicant if they let you test them very painfully. I am interested in games I can play where mastery also serves as a potential initial triage and could lead to interesting discussions.

Just as I like project euler gamified as a fake ideal programming project, I would like a systems game where the point is optimizing for the worst case with minimal tools.

Add an IDE, a choice of editors, all kinds of softskills requirements that are more significant to an employer than these base primary skills. Now, I wonder why I am working for free as I am no longer just practicing our core/universal skills in an idealized/timeless environment. The better place to do that form of showing off work realistic skills is in OSS projects.