First round - typical HR interview. The guy was really nice and friendly, gave many insights about the company and the role. I was asked to share what I know about SumUp, about my experience, what I value at work and so on, all usual questions. Second round - homework. Several programming assignments to be completed on an online platform. Read the initial description of this round carefully. Tasks: an easy-level leetcode challenge, sql, pandas + visualization, one etl-like task and one data science-related coding. Took me about 5 hours to complete. Found this challenge to be a good one and relevant to check hands-on knowledge of programming for doing data science/ML. Third round - technical interview. To be honest, I found it rather disappointing. For the most part this round consisted of beginner-level data science questions prepared by the interviewers beforehand asked one after the other. They also asked me to describe how I implemented my last project, but didn't ask anything about the details and choices I made. I believe the interview for senior-level positions should be focusing on what and how the candidate implemented, which choices they made, how they understand and address the trade-offs of different approaches. There was also a question about which features would I build for a use-case described by the interviewers. There were no system design questions, no specific questions about technologies (just whether I worked with this or that or not).