Observability as Code (OaC) at Airbnb defines alerts, dashboards, and SLOs through code, mirroring software development practices. While this process ensures disciplined alert definitions, validating alert behavior in production was a significant challenge. This gap led to either excessive alert noise or missed incidents, hindering developer workflow. To address this, Airbnb built accessible feedback loops for previewing and validating alert behavior before code submission. This innovation dramatically reduced development cycles from weeks to minutes. The company's OaC goal is for product teams to receive out-of-the-box monitoring from platform teams, achieving "zero touch" adoption. However, managing 300,000 alerts made iterating and validating OaC changes costly and risky. Traditional code reviews and unit tests could not predict how alerts would behave with real-world data, leading to a weeks-long validation process. Airbnb rebuilt its OaC platform focusing on local-first development, Change Reports, and bulk backtesting against historical data. This allowed engineers to validate alert templates quickly and efficiently. Key learnings included prioritizing compatibility over novelty, implementing robust guardrails, and owning the full development surface area for improved developer experience. The impact has been a successful migration of 300,000 alerts to Prometheus, collapsed development cycles, and a significant reduction in alert noise, fostering a culture of alert hygiene.