Build The Next Generation Of Python Web Applications With FastAPI


April 19th, 2020

58 mins 34 secs

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About this Episode


Python has an embarrasment of riches when it comes to web frameworks, each with their own particular strengths. FastAPI is a new entrant that has been quickly gaining popularity as a performant and easy to use toolchain for building RESTful web services. In this episode Sebastián Ramirez shares the story of the frustrations that led him to create a new framework, how he put in the extra effort to make the developer experience as smooth and painless as possible, and how he embraces extensability with lightweight dependency injection and a straightforward plugin interface. If you are starting a new web application today then FastAPI should be at the top of your list.


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  • Your host as usual is Tobias Macey and today I’m interviewing Sebastián Ramirez about FastAPI, a framework for building production ready APIs in Python 3


  • Introductions
  • How did you get introduced to Python?
  • Can you start by describing what FastAPI is?
    • What are the main frustrations that you ran into with other frameworks that motivated you to create an entirely new one?
  • What are some of the main use cases that FastAPI is designed for?
  • Many web frameworks focus on managing the end-to-end functionality of a website, including the UI. Why did you focus on just API capabilities?
    • What are the benefits of building an API only framework?
    • If you wanted to integrate a presentation layer, what would be involved in that effort?
  • What API formats does FastAPI support?
    • What would be involved in adding support for additional specifications such as GraphQL or JSON-LD?
  • There are a huge number of web frameworks available just in the Python ecosystem. How does FastAPI fit into that landscape and why might someone choose it over the other options?
  • Can you share your design philosophy for the project?
    • What are your main sources of inspiration for the framework?
    • You have also built the Typer CLI library which you refer to as the little sibling of FastAPI. How have your experiences building these two projects influenced their counterpart’s evolution?
  • What are the benefits of incorporating type annotations into a web framework and in what ways do they manifest in its functionality?
  • What is the workflow for a developer building a complex application in FastAPI?
  • Can you describe how FastAPI itself is architected and how its design has evolved since you first began working on it?
    • What are the extension points that are available for someone to build plugins for FastAPI?
  • What are some of the challenges that you have faced in building an async framework that is leveraging the new ASGI specification?
  • What are some sharp edges that users should keep an eye out for?
  • What are some unique or underutilized features of FastAPI that users might not be aware of?
  • What are some of the most interesting, unexpected, or innovative ways that you have seen FastAPI used?
  • When is FastAPI the wrong choice?
  • What are some of the most interesting, unexpected, or challenging lessons that you have learned in the process of building and maintaining FastAPI?
  • What do you have planned for the future of the project?

Keep In Touch

@tiangolo on Twitter. @tiangolo on GitHub.


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The intro and outro music is from Requiem for a Fish The Freak Fandango Orchestra / CC BY-SA