Spring Boot, a framework for creating stand-alone, production-grade applications, is often used in combination with a separate frontend framework like React. This setup benefits from the use of Spring Security to handle authentication and authorization, especially in multi-tenant environments where roles and permissions are critical. A common configuration involves using Spring Boot as the backend with an external authentication service, like PropelAuth, which simplifies the authentication process by handling it outside of the backend. The backend must validate authentication information and ensure users have the necessary permissions to make requests, often using JWTs for token validation. PropelAuth supports B2B and multi-tenant setups by providing features like organizations, role-based access control, and enterprise SSO, allowing users to belong to multiple organizations with specific roles. The backend can restrict access to routes based on users' roles and permissions using an AuthorizationManager, which checks if users have the correct roles and permissions within their organization. This setup also accommodates dynamic authorization changes based on factors like payment plans, utilizing PropelAuth's Role Mappings to adjust permissions without altering the code.