So here's the issue: they warn you about these reviews and the interview process. I was ok with trying a case study. They even send you information about their feedback philosophy. But when it comes down to it: a lot of a work, and no feedback on the rejection at all. They say one potential reason for rejection is poor fit for the job - well they knew that before they send the case study. They say they get too many submissions - sure that excuse works if they weren't the ones the invited you to complete a case study. They seem to be insulated and fall short of their own feedback philosophy - that's the real red flag.