What is an effective strategy for maintaining access controls across multiple AWS accounts?

Using AWS Organizations to simplify policy application is an effective strategy for maintaining access controls across multiple AWS accounts due to its centralized management capabilities. AWS Organizations allows users to manage billing, compliance, and access permissions across all accounts from a single interface, which greatly enhances the efficiency and consistency of policy application.

By creating organizational units (OUs) within AWS Organizations, administrators can apply Service Control Policies (SCPs) that govern permissions across all accounts or specific groups of accounts. This ensures that access controls are uniformly enforced, reducing the likelihood of configuration drift and enhancing overall security. Additionally, it simplifies the operational overhead associated with managing multiple accounts, as changes can be made once at an organizational level rather than needing to be applied individually across each account.

This approach provides a clear and scalable method for managing permissions, especially in environments where multiple accounts are necessary for different teams or projects. In contrast, managing permissions through individual IAM policies or consolidating access permissions into one IAM role tends to be more cumbersome, as it requires significant manual effort and can lead to inconsistencies or errors. Applying permissions only at the bucket level lacks the comprehensive control needed over a multi-account environment, making it less suitable for maintaining robust access management practices across AWS accounts.