The process took around 2 months, everyone was very nice and respectful at every step. All in all I had 6 interviews besides the preparatory meetings with HR representatives: in the first interview a system's design was requested. A live collaboration coding exercise via hackerrank followed and then some behavioural style interviews with different key people. All in all it was very well organised, and I got all the info I needed at each step, even though I consider the process a bit too long.