There was an initial 1-hour video interview with the department heads, where they asked about past experiences and theoretical questions about the field (data science, machine learning). They were nice, and I got invited for a personal trial day 3 weeks later. They explained what I would be working on, and I had to complete a task in about 2-3 hours at the end. It went well, but in the end I was not selected. The company is in the gambling industry, they run online casinos and sports betting sites, which they are quite secretive about, but they told me straight up during the first interview.