We have built backends in Node.js, Django, and Laravel. For most of our client projects in 2025, we default to Python FastAPI. Here is the reasoning.
Technology choices are not tribal. We use the right tool for the job. But when a client does not have strong preferences and the project is a typical API-backed web or mobile application, we default to Python FastAPI with PostgreSQL — and here is why.
Async performance at Django simplicity
FastAPI is built on Starlette (async) and Pydantic (validation). It handles 20,000+ requests per second on a single core in benchmarks — comparable to Node.js, far ahead of synchronous Django or Flask. For I/O-bound workloads (database queries, payment callbacks, email sending), async matters enormously.
Automatic API documentation
FastAPI generates OpenAPI documentation from your type hints automatically. Every endpoint has a live interactive docs page at /docs. For client projects where a mobile developer team is consuming the API in parallel, this saves days of documentation effort and eliminates the "what does this field return?" questions.
Type safety without TypeScript ceremony
Pydantic v2 provides runtime type validation with Python type hints. You define a data model once and it serves as both the API schema and the database model basis (via SQLAlchemy). The tight integration between these three libraries — FastAPI, Pydantic, SQLAlchemy — means less boilerplate than any equivalent in Django or Node.
Python's AI/ML ecosystem is unbeaten
When a project evolves to include recommendations, fraud detection, or natural language processing, Python's ecosystem (scikit-learn, transformers, LangChain, OpenAI SDK) slots in natively. We have added AI features to FastAPI services in days that would take weeks to implement via a Node.js microservice boundary.
When we do not use FastAPI
- Real-time collaborative features (WebSocket-heavy apps) — we use Node.js + Socket.io.
- WordPress-adjacent CMS sites — PHP is still the practical choice.
- Mobile backend for Firebase projects — Firebase Functions in TypeScript.
