Yelp has a design challenge for the product designer position. Many of my colleagues and I were invited to do the design challenge, which took at least 20 hours, and they rejected most people with a generic copy-pasted response without even interviewing them. I was able to reach a 1st round interview and present my design challenge, then 2 days later I was rejected. The rejection was fine, bit it was when I asked for additional feedback on my interview, the recruiter refused "due to company policy." This is a highly unprofessional interview process that is very much a waste of everyone's time. I will not be applying to Yelp again.