Straight forward process but very long and arduous with plenty of stages. I'd say it needs to be refined. Interviewers were very professional and rapport building was easy. I would suggest cutting down on the numerous steps in the interview

Very long process, 6 interviews and a take home task before being rejected. Brief of the task said don't overcomplicate it but the feedback I received was that I still didn't go into enough detail. So be prepared to spend a lot of time for the interviews. Generally friendly interviewers and easy interview questions, very straight forward standard a/b testing and causal inference questions. Despite this was rejected, would have brushed up on my domain knowledge in retrospect as I probably wasn't very clear answering causal inference questions to a product very different to my experience. The sql test was very easy and I completed all questions correctly, but got some negative feedback on this as I wasn't familiar with postgresql quirks around dates which they marked me down on.