It's fairly easy. Your first interview is short (~20 minutes) then if they like you, you'll get another one (60-90 minutes), usually conducted by two different people. I did my first interview on a Wednesday and my second one on a Friday and was hired by 6:30 p.m. on that same Friday. Fair warning: they will give you a time window for when they'll call you back after each interview but it'll probably be 1-2 hours after the time they said.