For the summer internship for college students, there was first a 1:1 interview on your college campus, most likely through the Career and Job Center. This was with a manager, senior manager, or more rarely, a partner. If you made it past the 1st round, then you were invited to do in-house interviews, which consisted of 3 1:1 interviews, with managers, senior managers, directors, and/or partners. You were also taken out to lunch or dinner (depending on the time of your visit) with fellow interviewees and senior associates or 2nd/3rd year associates. Generally, there are no technical questions. Just behavioral. Though maybe you will get an oddball interviewer and get asked how to account for revenue recognition or something basic like that. Around the 2 interview days there would also be 1-3 firm social/networking events that you should try to attend to meet other employees and get a sense for the people at the company, what they like about the company, and what they don't like (though they are more hesitant to reveal the latter). Throughout all of the interaction processes, make sure you are consciously presenting yourself in a way that would want the company to hire you... friendly, smart, diligent worker.