There were two rounds, both with live questioning.

The first round lasted 2 hours, and the second, I think, was a bit over 1 hour.

The first round was with members of the team and the hiring manager (who was a bit late).

The second round was with a team lead, the hiring manager again, and one more team member.

The first interview was quite tough. They asked me specific questions about how compiling C++ code worked, how linking worked (e.g., what kind of symbols get exported where and when), and a few more I cannot quite recall. I knew answers to maybe half the questions and struggled with the rest. They kept asking though and wanted to know what I thought was happening.

After that, the first exercise was to review a piece of their code. I struggled to properly understand the 400 lines of code quickly, and I also think this was not quite what they intended. The code was a bit messy and complex, and there was one function in particular that was quite hard to understand. I think I flunked that part because I focused way too much on the code itself rather than the review.

After that, a quick pause, and then on with a coding exercise (some list structure - not quite sure anymore) plus some follow-up questions. This was the easiest part of the interview.

Second interview was with the hiring manager again, the group head, and one more member of the team.

It was a live coding exercise again. I think I had to merge an arbitrary number of arrays quickly and efficiently. I did not know the solution on the spot and suggested like 10 different ones. They every time asked me questions and wanted to know the algorithmic complexity, etc., and finally led me into the correct direction.

I ended up with a somewhat done solution after 45 minutes or so, which was when we said, "Okay, this is enough." Then there was one more question on a feature of C++ that I use in my day-to-day work, plus some in-depth questions about that feature (how does the compiler realize it internally).