The load was for election night, which is more than likely a full order of magnitude, or two above their normal traffic levels. So their normal setup of RoR is

The load was for election night, which is more than likely a full order of magnitude, or two above their normal traffic levels. So their normal setup of RoR is fine for normal amounts of load, but would fail under that expected spike. So they used all their page-creation code in rails, but instead of serving it out like normal, they create the static files, and serve those. You lose out on interactivity, but make up for it in performance.