I've never seen this. I would also simply ask if there were an alternative interview process. If not, I'd politely decline to continue. This sort of interview s

I've never seen this. I would also simply ask if there were an alternative interview process. If not, I'd politely decline to continue. This sort of interview seems like it's better than algorithm bingo on the whiteboard. In reality it's either an attempt to get free (or discounted) work or else contrived and therefore still removed enough from the actual day-to-day of the job as to be less than useful as a measure of fit and ability.