Applied through a referral. Was contacted by a recruiter and then did a phone screen with some senior data scientist. Got asked leetcode hard, my PhD projects, some statistics such as distributions, Bayesian formula type of questions (actual math). Didn't make it to the final onsite. I answered all questions in 57 min and to my surprise in the last 3 min, got asked to compute conditional probability using Bayesian question (provided false positive, false negative, etc.) that needed me to put some numbers in the formula and solve it in just couple minutes. Most companies allow their applicants to ask some questions in the last 5 min though.