I got contacted via a resume drop after a forum on campus about Big Data that a Yelp Representative attended. I got contacted by a recruiter about 6 months after the event - which totally worked out for me. I was contacted Sunday night, and had my phone interview that Tuesday. It was 25 minutes, and the recruiter just asked me if I had experience in a variety of platforms (did I have experience with Android for instance), what languages I was most comfortable with, etc. Then she asked me rapid-fire random tech questions - spanning random Unix knowledge/SQL etc, as well as basic byte trivia and some quick algorithm trivia, as well as pretty specific internet protocol stuff. At the end of the interview, she told me I had done well, that I was going on to the next round, which would be a 45 minute coding interview over Skype. I haven't had that next interview yet- but here's hoping!

Hackerrank challenge followed by a call with a recruiter. Then, an techinical phone screen of average difficulty followed by and onsite of total of 4 interviews which cover both technical interviews (think DS, algo + system design) and behavioural interviews. Everyone is very friendly, company heavily focuses on maintaining good WLB for employees and developing interesting product features.