The first interview was about 1.5 hours with one of the team members. This colleague asked questions about the day-to-day problems they are dealing with at Via.

Those were hard questions with no single true answer, and I felt the goal was to see how I think about problems in this domain.

Then there was a home assignment with a pretty hard question, which had multiple sub-questions. It took me a couple of days to complete, but I enjoyed working on it and was really excited that this is in the company's domain.

Then there was a second technical interview with another team member, which was mostly around the home assignment I submitted.

Finally, there was an interview with an HR person and the group lead. Both were personal, and I think they were aimed to see if I fit the group culture.

Not anything I can disclose, and they differ from interview to interview.

My best advice (this is what I did to prepare) is to think for yourself what kinds of problems you think they are dealing with in the algorithms department at Via, and go into the state of mind of problems from that domain.