The entire process was odd.
The recruiter screen took a full hour, the longest I've ever had. They call it "Life Story" interview and they seem very proud of it... The recruiter was very professional but I'd rather not spend that much time at this stage that doesn't influence the next steps much...
The next interview was "Problem Solving". I'm a very experienced interviewer and I've interviewed over 300 candidates over the past 5 years. Based on my experience, the moment I saw the interviewer, I knew I would fail: the interviewer looked tired and wasn't motivated at all about the conservation; maybe I look bad on that day? or something on my profile looks wrong to him? The question I had was not a typical case study interview you would expect for a mainstream tech company. Instead, a "how would you use data to help xxxxxx" was asked. It's open ended as expected; however, I never felt the interviewer "was really working with me to solve the problem" even though he said so in the very beginning. Very similar to other feedbacks, the interviewer is arrogant, he clearly had his own ideas and was expecting the interviewee to be able to guess what he was thinking. If your ideas were different, whether it's good or bad (who cares), your rejection is already on the way even the interview hasn't finished yet. If you "were really working with the candidate", and you "didn't like his ideas", should you at least "try to get him to catch your ideas you think that 'are perfect'?"
If you are very serious about working for this company, general preparation doesn't help: they have unique hiring philosophies. Go make friends with some current employees apparently they got hired they knew how to nail the interviews, and whether there are particular interviewers you would want to avoid (simply asking for rescheduling would do it, it's a random match) so that you know how to make the interview not to decide to reject you in the first 30 seconds. If you are just curious about the process, imagine an interview in which the only question you are being asked is "hey, how do you operate a spacecraft?" and then the interviewer wait to keep notes of your responses, even though he's pretty sure you never even seen a spacecraft.
My long-time curiosity was how this company turned around in the past couple of years and became an industry leader, and what was the role of its DS org in it. Was hoping to get an answer by talking to some great people from the company... I guess I'll try again after a year, to see if I get better matched to someone from whom I could get that answer.
Overall, the time I spent is very well worth it, I learnt how good the other teams I interviewed with are, so I'm happily accepting their offer. There is no regret with Shopify.