The performance improvements have probably NOTHING to do with node.js but with the re-architecture goals set by the team: "For our inevitable rearchitecting an

The performance improvements have probably NOTHING to do with node.js but with the re-architecture goals set by the team: "For our inevitable rearchitecting and rewrite, we want to cache content aggressively, store templates client-side (with the ability to invalidate and update them from the server) and keep all state purely client side." Better understanding of the problem and experience running the system were probably key for building the new high-performance architecture. Obviously, old one lacked these big advantages.