AWS Cognito and Microsoft Entra ID: Authentication as Part of the Ecosystem

Introduction

If Auth0 is the “hired expert” for authentication, then AWS Cognito and Microsoft Entra ID are the “system engineers” from tech giants. These services don’t just solve login — they are deeply integrated into their ecosystems and work best when you’re already using the cloud that created them.

AWS Cognito: Authentication for AWS-Native Applications

The Big Promise: AWS claims that Cognito is the “gateway” for your users into AWS. It’s designed to seamlessly integrate with other AWS services, such as Lambda for business logic or API Gateway for building APIs.

Reality: Cognito consists of two parts:

• User Pools: The database of your users that handles registration, login, and profiles.
• Identity Pools: The “bridge” that provides users with access to other AWS services (like S3).

Pros:

• Deep integration: If your project is fully built on AWS, Cognito fits like a glove. You can use it to authenticate into S3, API Gateway, and other services with minimal effort.
• Scalability: Like everything in AWS, Cognito scales effortlessly and can handle virtually any number of users.

Cons (a.k.a. reality):

• Complexity: The AWS Console can be confusing. Configuring Cognito is not always intuitive and sometimes feels like searching for the right switch in an airplane cockpit.
• Specificity: Cognito is best suited for AWS applications. You can use it outside the AWS ecosystem, but it won’t be as convenient as Auth0.

Microsoft Entra ID: Identity for the Enterprise World

The Big Promise: Microsoft Entra ID (formerly Azure Active Directory) is the next step in the evolution of Active Directory — but for the cloud. It promises to be the central hub for managing all corporate users, their access, and policies.

Reality:

• Pros:

  • Integration with Microsoft 365: If your company uses Office 365, Entra ID is already your IdP. This makes SSO setup incredibly convenient.
  • Strong enterprise features: Entra ID includes advanced security policies, role-based access management, and a wide range of enterprise-grade tools.

• Cons (a.k.a. reality):

  • Overkill: For a small project or startup, Entra ID is like using a castle lock on a bicycle. Its complexity and features are excessive.
  • Licensing: The licensing model can be confusing and costly for small teams.

For Independent Developers and Small Teams

• AWS Cognito is a good choice if you’re already building your product on AWS and don’t want to step outside the ecosystem. It grows with your project.
• Microsoft Entra ID is more of a B2B solution, designed to integrate into corporate environments. If your customer is a large company using Microsoft 365, Entra ID integration becomes a key advantage. For a typical B2C app, however, it’s usually not a good fit.

Ironic Verdict

Cognito and Entra ID are giants that thrive in their own “sandboxes.” They can be incredibly powerful — but only if you play by their rules. If you’re already in their ecosystem, they’ll be your best friends. If not, you’re better off looking elsewhere.