AWS Organizations and Multi-Account Strategy: Landing Zone, SCPs, and Cross-Account Access Running everything in a single AWS account is the most common infrastructure mistake startups make. It starts simple, but by the time you have production workloads, staging environments, CI/CD pipelines, and developer sandboxes sharing the same account, you have a security boundary problem. One misconfigured IAM policy in a dev environment can expose production data. A runaway Lambda in staging can hit your account-wide service limits and take down production. AWS Organizations lets you create a hierarchy of accounts with centralized billing and governance. The recommended structure is an organizational unit (OU) tree: a Security OU for audit and logging accounts, an Infrastructure OU for shared services like networking and DNS, a Workloads OU split into Production and Non-Production, and a Sandbox OU for developer experimentation.…