I don't think they have any real roles and seem super comfortable with just wasting everyone's time including their engineers' who seem exhausted for their process. I applied through a referral and actually had quite a bit of overlap. I got a totally disinterested panel interviewer who didn't even seem interested in interviewing. I had to pry the question out of him and he pasted the question incorrectly and started a discussion about rounding without really knowing why we needed to talk about it. I did get all the test cases correct however. Think I dodged a bullet here.