As a developer advocate working with web and mobile application developers, I’ve often heard about the need to maintain consistent user authentication in the unlikely event of a regional service interruption. The increasing use of agentic AI, microservices, automation, and service accounts has sparked a similar need for machine-to-machine authentication. Today, I’m excited to share two important updates to Amazon Cognito: multi-Region replication for improved resilience, and support for customer managed keys for more control encryption control.

Many applications rely on Amazon Cognito to handle user and machine-to-machine authentication, and to manage user profiles. When building for high availability, having consistent data across different AWS Regions is a key approach, and until now, achieving that consistency came with significant challenges. Engineering teams spent significant time building and maintaining custom replication solutions to synchronize configurations across Regions. Manual export and import of user data between Regions created security risks from potential data exposure and introduced opportunities for data inconsistencies. During regional transitions, end users experienced disruptions like forced password resets and re-authentication. For machine-to-machine communications, teams had to create new app clients in the secondary region, which meant reconfiguring their applications and updating OAuth-protected resources to accept access tokens issued by the new regional issuer. These challenges made it difficult to maintain uninterrupted operations across Regions.