I applied through my university's career center and was called 2-3 days thereafter. An appointment for the interview was arranged. The interview itself was very casual and conversational. Questions ranged from what my college major was, what classes I took, general questions about my past experiences, and some "philosophical" questions about why I'm interested in UBS and this position, and where my motivation comes from. Be sure to ask questions to further show your interest and let the interviewer know that you are serious about getting the internship and not that you only applied because it was an open position. Do research on the company, the division of the company you will be in, and what kind of clients the division mainly deals with. Also having a working knowledge of the financial services industry would also help in turning the interview into more of a personable conversation. I was called later and received the formal offer.