One coding challenge was given, which is supposed to be 3-4 hours in one sitting, but it should take an average programmer at least 10 hours to finish. It feels like throwing you a big class assignment to help them write the codes that their engineers do not want to do at work. Two rounds of the phone interviews with the Engineering team. Coding questions are very relative to the real work done at Quantcast. I got positive feedback from those interviews and was expected to move me forward on the onsite interviews, but the recruiter requested another round of interview asking me probability and machine learning modeling question. I had interviewed with many companies, and this is the first one asking me how to calculate the probability of flipping coins. Yes, I did take my probability class, but getting those question on a software engineer technical interview is out of my imagination. Then I got an email after the weird modeling interview and said they decided to move forward with other candidates. I do not know whether the other candidates have been through this process, but it just happened to me. I highly recommend the people who are about to apply to Quantcast actively communicate with your recruiter on the hiring process, the expectation of the position you are applying to, and the content of the interview.