The initial interview was an online digital interview where they record your response to 9 behavorial questions. The video is then sent off to the hiring team for review, and, if they liked your responses, you get a call to come to their campus for an "interview," you'll understand the quotes later.
You arrive on campus, where you are greeted at the door by another intern. You are then introduced to the Director who manages the entire show for the day, he was a great guy who stressed that there were not going to be two interviews today, but two conversations as he calls them.
Both interviews were extraordinarily laid back. I interviewed with a system analyst and systems architect, we had a casual conversation that started with just one question, why do you want to work for Optum and then never another question. We spent the entire 25 minutes for each interview talking about whatever topic resulted from that one question. Both interviewers were very personable and shared any knowledge I asked about, nothing was kept top secret. Neither interview was technical in nature, the Director made it a point when someone asked him if we would be writing code in the interviews to point out that there is nothing he can ask you in an interview about what you've learned in college that will be relevant to what they are doing, so why make us nervous wrecks trying to write simple code when they can spend time making sure you are a fit for the company, they will teach you their platforms later.
The day ended with a catered lunch with employees and fellow interns and some more great conversation with those people one on one.
The interview was on a Friday and they start contacting applicants the following Monday and conclude all contact by Wednesday, so you find out very quickly whether or not you were accepted in to the program.