Revolut Backend Engineer interview questions

First I had a meeting with a recruiter. She was very nice and helpful. It was just around 15' talking about my past experiences etc First code interview: ~1h with a revolut engineer (and I think a shadow interviewer but I don't remember 100%). It was about solving a few problems about a URL shortener. The problems per-se were not difficult, but you were expected to write test, good code etc. The interviewer would at some points ask you to explain why you chose to do it that way, if there were other alternatives, what the main issues with the approach may be etc. At the end of the interview there was around 10 minutes of technical questions. Why would you store this in a hash table? What is the time/space complexity of this? At the end there was some reserved time to ask any questions to the interviewers. Second code interview: Two Revolut engineers and a shadow interviewer.~1:15h. Solve a basic bank transfer service. As before, the interviewers asked about my train of though, issues etc. After writing the code, we got to technical questions. They put a lot of focus on concurrency, locking etc. It was supposed to be ~15mins but got stretched to ~30mins. At the end there was some reserved time to ask any questions to the interviewers. Finally I meet with my prospective team manager and the backend lead. This was a more informal meeting, just asking about my experience and sharing a bit of the day-to-day of the team. All in all it was a very good interview experience.