This walkthrough needs JavaScript. In short: a spot capacity orchestrator, as this practice designs it, runs interruptible work on capacity that a private cloud can take back with 120 seconds' notice. The control plane decides where capacity comes from; the node decides what happens when it goes away, from a contract it already holds, so no notice is ever routed through a central service. Told as a night market on a stadium car park: the whistle blows, the steward packs the stall, and the office across the road only finds the replacement.