There were 2 separate interviews on the same day. Each interview was conducted with 2 people asking questions at a time. They use the STAR format with the addition on what you learned and how you applied it going forward. Be prepared to give examples using specific situations. They were more interested in what you learned from the situations. Also ask them questions about the environment which you will work, their experience, future growth and any thing else to aide in your decision making process. You are interviewing them as well so be engaged.