How does Rails handle large-scale system design for globally distributed authentication systems?

Rails integrates with global identity providers using OAuth2, SSO, JWT, and federated authentication systems.

Global authentication systems require centralized identity providers and decentralized verification. Rails validates JWT tokens issued by providers like Auth0 or Cognito. Federated identity allows users to authenticate across regions and services. Session management is often stateless, enabling horizontal scaling. Token rotation and revocation mechanisms are critical for security.