Two Excellent Frameworks, Different Strengths

Python offers two outstanding web frameworks: Django, the full-featured "batteries included" framework, and FastAPI, the modern async-first framework built for APIs. At Nexis Limited, we use both in production — Django for our SaaS products (Ultimate HRM, Digital Menu, Digital School) and FastAPI for API-centric services and ML model serving.

Django: The Complete Package

Django is a full-stack web framework that includes an ORM, authentication system, admin interface, form handling, template engine, and migration system out of the box. Its "batteries included" philosophy means you can build a complete web application without choosing and integrating dozens of third-party packages.

When to Choose Django

  • Building a full web application with server-rendered pages or an admin dashboard
  • Projects that benefit from Django's ORM and migration system
  • Applications requiring user authentication, session management, and CSRF protection
  • Content-heavy sites or applications with complex data models
  • Teams that value convention over configuration and rapid development

FastAPI: Performance and Modern Design

FastAPI is built on Starlette (ASGI) and Pydantic, providing automatic request validation, serialization, and OpenAPI documentation. Its async-first design makes it ideal for I/O-bound services that handle many concurrent connections.

When to Choose FastAPI

  • Building REST or GraphQL APIs without server-rendered UI
  • High-concurrency services (WebSocket handlers, chat applications, streaming)
  • Machine learning model serving where async inference is beneficial
  • Microservices that need auto-generated API documentation
  • Projects where type hints and runtime validation are priorities

Performance Comparison

FastAPI significantly outperforms Django in raw request throughput because it uses asynchronous request handling (ASGI vs WSGI). For I/O-bound workloads like database queries and external API calls, FastAPI handles more concurrent requests with fewer resources. For CPU-bound workloads, the difference is less significant since both are limited by Python's GIL.

Our Production Usage

In our SaaS products, Django's ORM, admin interface, and authentication system accelerate development and simplify maintenance. Our Ultimate HRM system uses Django's admin for internal data management, and its migration framework handles schema changes across hundreds of tenants.

For API-centric services — Bondorix's analytics endpoints and our ML inference pipeline — FastAPI provides better performance and auto-generated Swagger documentation that our frontend teams consume directly.

Conclusion

Django and FastAPI are not competitors — they serve different needs. Django is the right choice when you need a complete web application framework with rich built-in features. FastAPI is the right choice when you need a high-performance API server with modern Python patterns. Choose based on your project's requirements, not hype.

Building a Python application? Our Python team has deep experience with both frameworks.