Yeah, I've co-organized and attended multiple hackathons, and one of our organization principles is "code is key", to combat powerpoint-only submissions. That

Yeah, I've co-organized and attended multiple hackathons, and one of our organization principles is "code is key", to combat powerpoint-only submissions. That means that there is a code-screening after the submission deadline that ensures that what was demoed was also implemented, and also gives some points in the overall scoring based on execution. We have seen submissions that include a fully-fleged backend including tests, as well as completely faked demos (which were easy to pick up, as what they promised was too far removed from reality).