Make sure you know the company and get comfortable with behavioral type of questions, but the interviewers are very nice so they will make you feel more comfortable. Come in with questions to ask. Overall just make sure you prepare prior to the first interview, you only have one chance to get into the second round of interviews.

The night before the interview we had an informal dinner to meet with the interviewers and other interviewees. The interviewers were very nice and conversation driven. The interview the next day was made up of two 30-minute sessions with two interviewers in each session, so four interviewers total. Most of the interview seemed conversation driven, and with some behavioral interview questions.