No, never. If the role needed someone with specific expertise or if CORS was a “hot item” for day to day development, then sure. But I’ve found that I usually don’t need to ask very complex questions to figure out if someone has skills or not.

Not OP. I'm starting to think that basic/mid level depth understanding of CORS is one of those canary-like items to judge if someone has a good grasp of web/http technologies. The other one is text encoding. You'd be surprised how many people don't know the difference between unicode and say utf8. It's all "black magic" to them at the end of the day.

Most people that haven’t run into encoding issues yet have no need to know the difference.

Thankfully basically everything is utf8 these days.

It absolutely is. Especially when it "doesn't work" (not configured correctly.) Can someone look at a browser log and figure out what's going on? It's not just a front end issue, either. I've seen backend engineers set up crazy CORS configurations for internal APIs that would've been better served with a proxy off of a single origin. I even ran into an "architect level" guy that had no understanding of how that would even work. "You can POST without CORS???" seriously...

Sounds like confirmation bias. I know CORS and I know the difference between utf8 and unicode and I'm smart. Therefore anyone who doesn't is a dumb dumb.