I have had many people reach out for advice on how to nail their demo interview.  I have been on both sides of the interview (interviewer and interviewee) and I have seen a few that have stood out but most lack both preparation and creativity.  Personally, demo interview are my favorite type of interview as they enable the interviewee to express their passion on a product and set themselves up for success (since often they can create the use case).  As the interviewer, it gives me insight into how you will demo in front of customers, respond to difficult questions and time management.  What I have seen after interviewing numerous sales engineers is that the best engineers do 3-5 of the following: