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

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.