There were 3 rounds of interviews and the whole process took about a month. The first interview was held over Skype by the current HR interns. Got a call a week later to set up a phone interview with one of the bosses. Got a call a few days later to set up an in-person interview with the Principal over coffee. I was surprised at how many rounds of interviews there were considering it was just an internship - but it did show me how much there team cares about hiring the right fit.