I'm pretty sure Jason uses Mupx for deployment to DigitalOcean (https://github.com/arunoda/meteor-up/tree/mupx).
For anyone interested, this package makes it super easy to setup all the tools and deploy to the servers (almost as easy as pushing to Heroku!).
I've had good experience in scaling using Mupx and Cluster (another package from the same team - https://github.com/meteorhacks/cluster)