It is quite long and detailed. Be prepared for about an hour long interview with a tour on top of that. It is a panel setting and they have different scenarios and questions to answer. Don't worry, one of the main things they are interviewing for is your problem solving skills. You may feel like you aren't doing amazing, but your probably are doing just fine. They want to see how you respond to stressful and problem solving type situations (esp if you don't know the answer).