Long, many rounds, many days of times, many efforts. Be prepared to spend tons of time, I mean tons of time, to get blown off for an interview that doesn't make any sense. You can pass 5 rounds and then fail one round because the interviewer is abrasive, aggressive, and asks ambiguous questions that don't make any sense. Recruiter will call you and say sorry you aren't passing, won't be any reason to why or any care. They say to be friendly but the interviews can be super direct. Be prepared to have to fit to their schedule, take countless days of vacation, and it will probably be a waste of your time. Be prepared to become an expert at a video conference and don't expect anything to be organized to your schedule.