Interview done with 2 staff engineers. It was smooth, they were very calm and clear. Although the questions did not seem to be prepared in advance, the topics were specifically discussed.

First HR call, nice one with a person in UK. Second one is with a Tech Lead who is gonna ask about your experience, this was very good too. After that, a code challenge is sent, there are four iterative excersises, not too hard, not too easy, I think was a fair one. The next stage is a system design interview, that one was tricky they give you a typical scenario where you provide a solution. I did not pass this one and I got the mail with the reject