Invited to a 1.5 hour interview with several Partners. Overall challenging technical questions were asked throughout the interview. For example, how a locking plier worked (required explaining that it was metastable and would collapse into two possible states, open and closed). Also, explaining how a projected keyboard captured the user's inputs. How does the rain sensor on a car work (based on total internal reflection changing the amount of light scattered). A gained a lot of experience with this challenging interview, so it was an overall good experience.