There are 3 interviews and a lunch. Your first interview will be with 3 managers who will ask simple personality questions to make sure you are a good fit. If hired you will be under one of these managers. The second interview is a technical interview. Brush up on your basic fluid dynamics. The questions are easy, but the stress of being in an interview doesn't help. Next someone will take you out to lunch. This person will be working in the position you are applying for and will have held that position for at least 2 years if not more. They are there for you to ask questions and see if you like the job. They are monitoring how conversational you are and how interested you are in the job based on the questions you ask and what you want to know. The final interview is with the office manager to discuss logistics of the job. What the job really is and what is expected of you. It may take a couple weeks to get an offer, don't be afraid to call them and bother them after 2 or 3 weeks of not hearing back.