Ask HN: How to Interview DevOps Candidates?

Over the last year I have transitioned from a software developer into a DevOps role. Changes at the company have meant that some of the more senior members of the team have left and I'm a position of needing to interview their replacements.

I'm comfortable interviewing developer candidates, but having never interviewed anyone for a DevOps position, I'm not sure what the best approach is to ensure that I do a good job identifying qualified candidates.

Should I quiz candidates on their knowledge of networking, on DNS, on tools like strace, etc? Is there a place for quizzing about general Linux knowledge, e.g. "what is grep used for?" I will give candidates an in-office software project to complete: a simple Python program or Bash script, but should I also give them contrived DevOps problems to solve? For example, "deploy this app to this VM"? Or "figure out why this application can't connect to its database."

Any tips or anecdotes about interviewing DevOps candidates, or about being a DevOps candidate, would be greatly appreciated. Thank you in advance!