FastAPI Agency
FastAPI is a modern Python framework for building fast APIs. Asynchronous and strongly typed, it rivals Node.js and Go while keeping Python's simplicity. We use it for your SaaS APIs, microservices and AI endpoints.
Build your API with FastAPI
FastAPI is a modern Python framework designed to build fast APIs. Its performance rivals Node.js and Go, while keeping Python's simplicity and readability.
Its strength is typing. Thanks to Pydantic, incoming data is validated automatically and the interactive documentation (OpenAPI/Swagger) is generated effortlessly: fewer bugs, and an always self-documented API.
We use it for the pieces where speed matters: a SaaS back-end, microservices, or endpoints that expose AI models. FastAPI complements Django more than it replaces it.
FastAPI solutions adapted to each context
A startup wants a fast API to power its web and mobile application.
An asynchronous, documented FastAPI API (OpenAPI), with authentication, data validation and a deployment ready to scale.
An organization wants to expose its computation or AI models through a secure API.
FastAPI endpoints exposing the models, with Pydantic validation, quota management and interactive documentation.
An SME needs to connect several software systems through interoperable services.
A FastAPI microservices architecture, asynchronous communication and a centralized API gateway.
An organization wants a reliable public API for its partners.
A versioned, documented and tested FastAPI API, with fine-grained access and API key management.
What we hold to on a FastAPI API, from data validation to scaling up.
Pydantic validation
Requests and responses are typed: invalid data is rejected before it ever reaches your business logic.
Living documentation
OpenAPI documentation is generated from the code, so it stays aligned with what the API actually does.
Async where it counts
On I/O workloads, a network call, a database query or an AI model won't block the other requests.
Access and quotas
OAuth2 or JWT authentication, with API keys and quotas when external partners consume the API.
The right framework
We don't push FastAPI everywhere: for a full back-office with ORM and admin, we recommend Django.
Automated tests
The API is covered by tests so its contracts don't break on the first refactor.
Versioning
An API opened to third parties is versioned, so your partners never absorb your internal changes.
From POC to product
An API that started as a proof of concept scales up without being rewritten from scratch.
Concrete custom development achievements
Identify levers to strengthen farm autonomy
An extranet to centralize all information and documentary resources
Offer a mortgage simulation that matches real lending conditions
Provide tools to master energy consumption
Carry out genomic sequencing projects
Identify levers to strengthen farm autonomy
An extranet to centralize all information and documentary resources
Offer a mortgage simulation that matches real lending conditions
Provide tools to master energy consumption
Carry out genomic sequencing projects
Identify levers to strengthen farm autonomy
An extranet to centralize all information and documentary resources
Offer a mortgage simulation that matches real lending conditions
Provide tools to master energy consumption
Carry out genomic sequencing projects
How we design your APIs with FastAPI.
For a complete application (admin, ORM, back-office), we go with Django. For a fast, asynchronous and strongly typed API, FastAPI is the best choice — it's a framework that is an alternative to Django and Flask we compare in detail on our blog. All three rely on Python and can perfectly coexist within the same project.
FastAPI relies on ASGI and async/await: it handles many concurrent requests without blocking. For I/O-bound workloads — network calls, databases, AI models — the gains are tangible compared to a synchronous framework.
Pydantic typing validates every request and response, the OpenAPI documentation is generated automatically, and we cover the API with automated tests. The result: a predictable, documented API that is easy to evolve.
What FastAPI brings to your API.
FastAPI combines Python's development speed with top-tier performance. It's the ideal framework when the API is at the heart of the product: mobile app, SaaS, third-party integrations.
End-to-end typing (Pydantic) strongly reduces errors: invalid data is rejected before reaching your business logic, and the documentation always stays in sync with the code.
Its native async support makes it an excellent choice to expose AI models or orchestrate calls to external services without degrading response times.
FastAPI's key strengths:
High performance thanks to async (ASGI)
Strict typing (Pydantic) that validates data automatically
OpenAPI/Swagger documentation generated automatically
Controlled scaling, from POC to product
Open standards (OpenAPI, JSON Schema, OAuth2)
Ideal for microservices and AI endpoints
Ready to get started?
From scoping to prototype, to AI integration.
We support your business software projects from start to finish.