MS Entra 101

Series Overview

Microsoft Entra ID (formerly Azure Active Directory) is Microsoft's cloud-based identity and access management service. Throughout my career building enterprise applications and microservices, MS Entra has been the backbone of authentication and authorization for countless projects.

This series distills years of hands-on experience into a practical guide for developers and architects working with Microsoft's identity platform.

What You'll Learn

This comprehensive series covers everything from foundational concepts to production-ready implementations:

Part 1: Introduction to Microsoft Entra ID

  • Understanding MS Entra ID (formerly Azure AD)

  • Core identity concepts and terminology

  • Tenants, directories, and organizational structure

  • Identity types: users, groups, service principals, managed identities

Part 2: Applications and Service Principals

  • App registrations vs enterprise applications

  • Service principals and their lifecycle

  • Multi-tenant application architecture

  • Redirect URIs and platform configurations

Part 3: Authentication Protocols and Flows

  • OAuth 2.0 implementation in MS Entra

  • OpenID Connect (OIDC) flows

  • SAML integration patterns

  • Authorization code flow, client credentials, and more

  • PKCE for public clients

Part 4: Tokens and Token Management

  • ID tokens, access tokens, and refresh tokens

  • JWT structure and claims

  • Token validation and verification

  • JWKS (JSON Web Key Sets) and key rotation

  • Token lifetimes and renewal strategies

  • Delegated vs application permissions

  • Microsoft Graph API permissions

  • Admin consent vs user consent

  • Permission scopes and least privilege

  • Consent frameworks and user experience

Part 6: Protecting APIs with MS Entra

  • Securing custom APIs with MS Entra

  • Token validation in backend services

  • Well-known endpoints and discovery

  • API middleware and authentication flows

  • Multi-tenant API considerations

Part 7: Advanced Features

  • Conditional Access policies

  • Multi-factor authentication (MFA)

  • B2B and B2C scenarios

  • Managed identities for Azure resources

  • Enterprise application SSO configurations

Part 8: Production Best Practices

  • Security best practices and hardening

  • Monitoring, logging, and auditing

  • Tenant management strategies

  • Troubleshooting common issues

  • Performance optimization

Who This Series Is For

  • Backend Developers: Building APIs secured with MS Entra

  • Full-Stack Engineers: Implementing authentication flows

  • Cloud Architects: Designing identity architecture

  • DevOps Engineers: Managing service principals and CI/CD integration

  • Security Engineers: Understanding identity-based security

Prerequisites

  • Basic understanding of authentication concepts (username/password, tokens)

  • Familiarity with REST APIs and HTTP

  • Experience with TypeScript/JavaScript or similar programming languages

  • Access to an Azure subscription (free tier works fine)

What Makes This Series Different

Rather than theoretical explanations, this series draws from real production experiences:

  • Actual code examples from microservices projects

  • Real-world scenarios and architecture decisions

  • Production issues I've encountered and resolved

  • Best practices learned through trial and error

  • No fake scenarios—everything is based on personal projects

Series Structure

Each part follows a consistent format:

  1. Personal Context: Real scenario from my experience

  2. Core Concepts: Fundamental knowledge

  3. Code Examples: Production-ready TypeScript/Node.js implementations

  4. Common Pitfalls: Issues I've faced and how to avoid them

  5. Best Practices: Lessons learned in production

Getting Started

Start with Part 1: Introduction to Microsoft Entra ID to build a solid foundation, then progress through each part sequentially. Each part builds on previous knowledge while remaining independently useful as reference material.


Author's Note: Microsoft rebranded Azure Active Directory to Microsoft Entra ID in 2023. You'll see both names in documentation and APIs. This series uses "MS Entra" or "Entra ID" primarily, with "Azure AD" noted where relevant for clarity.

Let's dive in!

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