They have nothing of the sort, as of last year. The ask politely that you not share the specific design prompts or your solutions, so that future candidates can

They have nothing of the sort, as of last year. The ask politely that you not share the specific design prompts or your solutions, so that future candidates can't copy you, but they're all over medium anyway. There are no legal teeth behind the request. This applies to the design prompt specifically, which is an early-stage take-home thing. I don't recall whether google had an NDA for the onsite interview portion itself, but I think their badge signin thing might have one baked in, and other companies of equivalent size had paper NDAs as part of checkin. Presumably they only care about you stealing the cool stuff you hear about, and you wouldn't be in danger for running with their (intentionally generic) interview prompts on your own.