Interviews were conducted by three panels of non-engineering managers, and the questions were from a purchased structured interview packet. Please google and research a structured interview - it's quite different and it marginalizes candidates. There is little opportunity to express individuality based on work experience with the firm beforehand. You will need to prepare a "anything to add?" speech for the end of the interview. Any and all engineering questions are based on making you think out loud. Don't ramble; take your time, take notes, and think out loud analytically... calmly. The questions are simple but have many possibly answers - it's about you producing an optimal chain of decisions for the panel to see. Using the structured interview clearly makes the job of the panelists easier, but I don't think it allows for an honest appreciation of the candidate and their experience. It's just HR being HR.