Our interview process has the candidate implement a couple (extremely simplistic) API routes, with the specific approach left up to the candidate. It’s more about having something they can talk through and evolve than it is about us looking for any specific approach.

Basically it exists as a way for us to have a starting point for talking about scalability topics, asking the candidate how they would evolve their implementation as we scale up the system. Does a pretty good job of giving us an idea of how they think through system design problems.