All questions were somehow related to criteos business model. First skype interview: Time series and probabilities Second skype statistics: Predicting CTR, deep dive into trees and logistic regression. The interviewer was amazingly nice and I felt like I was exchanging with a future colleague instead. On site coding interview: DFS on a matrix, classic leetcode On site second interview: Data analysis. The interviewer was ice cold, I did't feel comfortable at all. They handed me some paper with sheets and didn't give me time to go through the metrics and understand the numbers. They asked incomplete questions and didn't even understand what was expected from me so I started answering without even thinking because I felt so frustrated. Again, they were ice cold and had trouble expressing their need. I understand they are trained to carry interviews but i highly doubt this interviewer in particular was qualified what so ever. On site third interview: Data analysis again, handling missing data and statistical testing. I felt like applying for a data analyst position and after the on sites i knew that the second interview went really bad so I didn't expect much and didn't want to join criteo anymore after dealing with that particular interviewer. HR process was okay.