This guide explains how to implement Workload Identity Federation between AWS and Microsoft Entra ID. This modern approach enhances security by eliminating the need for static credentials. Organizations can securely connect services across AWS and Azure in a multi-cloud environment. Workload Identity Federation allows Azure to trust identities from external providers like AWS by validating OIDC tokens. This is particularly useful for cross-cloud pipelines and removing secret rotation overhead. The process involves setting up trust between AWS and Microsoft Entra ID. An AWS resource generates a short-lived OIDC token, which is then exchanged for an Azure access token. Permissions are attached to the Azure Function app via App Roles. Finally, the AWS resource calls the Azure Function using the obtained Azure token. The setup includes configuring IAM roles and federated credentials on both AWS and Azure. This detailed technical configuration enables secure service-to-service authentication without storing secrets. The guide concludes by validating the setup through a series of commands.