Give them a sample, 'The company you thought you're interviewing for is just a smoke screen, we're actually a stealth startup for a social network for pets" and

Give them a sample, 'The company you thought you're interviewing for is just a smoke screen, we're actually a stealth startup for a social network for pets" and have them diagram out how it might look for a MVP launch, 2 years in, 5 years in. What technology choices, how are they going to launch internationally, scale to hundreds of millions of pets, how are they going to achieve sub-second latency for the FindMyPet API, high-availability, do operational and business intelligence monitoring (and which BI metrics would he care about), unifying code across multiple platforms, etc. Most importantly they should light up when they get the question. Like someone just sat a piece of cake in-front of a fat kid.