First of all, congratulations! Getting interview invites is like the most exciting thing during this time of year. I remember how nervous I was, etc. My advice to you is going to sound cliche, but be yourself and be honest. Don't be anyone you're not. With that being said, if this years interviews will be anything like last years, then they will take you down for one interview with two faculty members. They ask you pre written questions that get a better sense of your thought process and what kind of person you are. They time this interview too (actually the shortest interview I went on), they put like 20 min on a timer so keep your answers concise and don't run too deep into tangents. If they have further interest in your answers, they will ask you follow up questions. There are some helpful interview prep sources on SDN that maybe someone else can help you navigate to. I didn't prep for interviews and just remembered to be myself because thats why we are all getting interviewed. Stay calm, relaxed, keep your head high, and feel like a boss and own it! Confidence in yourself goes a long way. Other than that, I can't help you with specific questions they asked, that was a year ago lol I don't remember but just know the basics. i.e. why you want to be a dentist? why UI? tell me about yourself? I believe its a closed file interview for UI but still know your app. Etc. you'll be fine
