It wasn't React, but Spike Brehm gave a lot of talks about Airbnb moving to "isomorphic JavaScript" with a library he created. It was called Rendr and it basically let you stitch together Backbone and Node and share code between the client and the server.

I remember being pretty interested in it at the time.

https://techcrunch.com/2013/04/19/airbnb-open-sources-rendr-...