Applied through a referral. The first step was an initial HackerRank-style assessment that was pretty straightforward and mostly Excel/data-analysis type work. I had to look up values, calculate metrics like profit, and answer practical business/math questions. The second round was with a TDOE and was much more intense. It focused on live problem solving, analytical reasoning, and probability/math concepts. I would recommend being comfortable with expected value, expected wait times, conditional probability, basic optimization, and explaining tradeoffs clearly. The interviewer cared a lot about how I broke down the problem, not just the final answer.