The interview involved 4 days of interviewing with multiple groups as they will see which group is your best fit within the organization. It seems like the interview process sets up the candidate for success by giving them mutliple chances by interviewing with multiple groups. The process is exhausting but worth it. The interview questions are a combination of technical and soft skills (give me an example of team work etc) type questions. People from diverse backgrounds work there, so even if you don't have the right background for the position, that is ok. All they are looking for is a person who can think critically and has good problem solving skills.