In 2011, Netflix released "Chaos Monkey"—a tool that randomly terminates production instances. This tool could exist because Netflix managed infrastructure as code. When instances died, CloudFormation (or the IaC tool of that time) automatically recreated identical instances. Chaos Monkey would have been a disaster with manually configured infrastructure.
CloudFormation is AWS's official IaC (Infrastructure as Code) service. Launched February 2011, it started with JSON templates and now defaults to YAML. In SOA-C02, CloudFormation isn't simply an "infrastructure creation tool" but rather an operational platform where "operators safely manage changes, detect state drift, and auto-recover on failure."