The selection procedure is mostly focused on assessing whether you can be a good fit personality-wise and it terms of general problem-solving skills, and little technical deep-dive, but your mileage may vary. As far as I know, the interviewing process can be quite different depending on the applicant, with more or fewer interviews required. As I speak Italian, some interviews were in English, other in Italian, depending on the interviewer. Most interviewing rounds were 1-on-1, except for a live problem solving interview, which had 2 interviewers. Interviewers were always polite and happy to answer questions, even if it meant overshooting the interview time-slot. From what I was told, interviewers are not aware of where you are in the interviewing process, or how you fared in other stages, to minimize their evaluation bias. At the start of the interviewing process you are assigned a recruiter that follows you during the process, and provides quick and constant feedbacks after every stage, plus answering questions if you have any. I appreciated their flexibility once I asked to speed up the recruiting procedure as I had other pending offers. The full process took about two months and a half.