My least favorite interview ever, was essentially "Implement this generic problem that our team had to solve, but you don't have the context of our infrastructure, and I'll criticize you every time you deviate from the actual solution we came up with because your solution wouldn't work in our context". It really felt like a "read my mind" type of problem.

No further point. Just glad to see you point out the relatively obvious point that you need to evaluate a question for someone who doesn't have your current context.

Definitely rough on candidates, but it does give a reasonable window into their thought processes and who the interact with other people.

However, it also feels quite artificial and stressful, which is a bad combo for a lot of people. Unless the position actually requires rapid fire system design and architecture, I'd be cautious using it as a primary filter. For most positions, designing a system architecture includes include some amount of research, reflection, iteration, etc.

In other words, you're evaluating something the job doesn't actually require (typically), and you're potentially missing out on people who might be brilliant architects given a little time to absorb the problem and think through options.