Question: This may seem like a dumb question but, doesn't a technical person administer technical interviews (coding / whiteboarding and systems design)?
So I had a behavioral screen with Meta some time ago and the in-house non-technical recruiter to my surprise oddly asked me a systems design question (I was expected to answer in like 5-15 minutes max which made no sense), I get that they want to get an idea of the candidate's 'product sense,' but I found it quite odd.
Recently, I came across another software engineering coaching platform I joined and went to their practice of DSA and system design interview prep sessions which they run weekly, which oddly I found that non-technical admins (executive assistants) ran, I think it was helpful for offloading administrative scheduling, but they didn't seem to help much since they're actually non-technical.
Yes, usually, the person administering the interview is technical. The reason is that the actual answer you come up with is just one part of the interview. Another element being evaluated is your ability to work with the interviewer and problem-solve. This second piece can only really be judged by a fellow engineer.
There's value in doing a mock interview even if the person conducting it is non-technical, since it helps you verbalize your thoughts and get out of your head.
I have seen recruiters ask technical questions before, but it's usually with more trivia based questions, and the questions are usually "you either got it right or you got it wrong". There's usually less back and forth because the recruiters are going off of a script of questions.
I imagine companies do this as a quick filter (short time, low stakes) before bringing in more technical people for longer interviews.
A lot of the value from a mock interview really is just talking with a human. But I do find it weird that a Meta recruiter asked a system design question... The most technical I've seen a recruiter get at Meta was ask some Android trivia (that was my initial round at Meta).
Meta is interesting as it does both system design and "product design" type questions for engineers with the latter being more focused on your product sense (i.e. what features to prioritize first, how would you measure the impact, etc). Product-centric design questions are more viable for a recruiter to administer.