Building Authentication, Authorization, and Directory Sync: A Practical Guide
In SaaS applications, authentication and authorization are critical. As your platform grows to serve multiple customers, each tenant wants to use their own identity provider (IDP), users need automatic provisioning from corporate directories, and access control must work across tenants. This guide covers OAuth 2.0/OIDC fundamentals, multi-tenant authentication patterns, SCIM-based directory synchronization, and practical implementation details. Understanding OAuth 2.0 and OIDC What is OAuth 2.0? OAuth 2.0 is an authorization framework that enables applications to access resources on behalf of users without sharing passwords. Think of it as a valet key for your digital resources - you give limited access without exposing your master credentials. ...