Lessons Learned using FastAPI in the Wild
Speaker
Graham Lyons
Graham Lyons is a software generalist with a fondness for Python and nearly 20 years of professional experience. He has worked for the BBC and eBay, amongst other companies, and has been working freelance since 2017. Graham is very keen on writing tests before code and all other aspects of the software development lifecycle that make it possible to deploy to production as soon as possible.
Abstract
This talk is for anyone curious about what it’s like to run FastAPI in production. An asynchronous web framework with automatically generated documentation and dependency injection, FastAPI has made huge gains in popularity and overtook Flask in the 2025 Stack Overflow Annual Developer Survey. FastAPI’s features are impressive and picking it up is easy, but beyond that what is it really like to run in production? What joys and pitfalls await those deploying the most popular Python web framework?
Description
In this talk attendees will learn about how dependency injection in FastAPI can help structure applications and aid testing. In testing FastAPI apps they will find out about verifying correctness of HTTP endpoints vs the documentation. From the automatically generated documentation they will see how simple it is to generate a client. Attendees will also find out about scaling FastAPI containers in a container orchestrator like Kubernetes and about how to spot performance problems which might arise in asynchronous Python applications.