(cockroach here)

Baidu is using it for a new application where previously they would have used sharded MySQL (https://www.cockroachlabs.com/customers/baidu/). Their dev team is fairly active on GitHub and Gitter if you want to ping them for more details.

Heroic Labs is using it for real-time, multi-player gaming development that can support a global userbase (https://www.cockroachlabs.com/customers/heroic-labs/). I'm not sure how gitter/github/HN active they are, but they work in open source, so they're probably pretty easy to connect with.