We’ve all been there. You spend two days wiring up authentication for a distributed project. It works perfectly on your machine with a mock provider or a local database, but the moment you try to integrate a real enterprise identity provider like Microsoft Entra ID , the wheels come off. Redirect URIs don't match, audience validation fails, and your local environment feels nothing like the production environment you're supposed to be targeting. When I started building out my latest CleanArchitecture template , I wanted to solve this once and for all. I wanted an architecture where switching between an open-source provider like Keycloak and an enterprise-grade one like Entra ID was a matter of a single configuration switch, not a week of refactoring. In this guide, I’m going to walk you through how to implement a production-ready Entra ID authentication flow within a .NET Aspire project.…