As your FastAPI applications grow in complexity, leveraging asynchronous programming becomes essential—especially when dealing with I/O-bound operations like database queries. Yet, many developers stumble into pitfalls when trying to "go async" in their data layer. In this article, I’ll explain how to run database queries asynchronously in FastAPI, walk through best practices, and show how…

Dependency injection is one of FastAPI’s most powerful features, enabling clean, modular, and testable code. But beyond simple function-based dependencies, FastAPI offers several advanced patterns that can make your applications even more flexible. In this article, we’ll explore some lesser-known techniques you can use to level up your FastAPI dependency management. Recap: What is Dependency…

One of FastAPI’s greatest strengths lies in its integration with Python type hints and Pydantic models. This lets you define input and output data structures—including validations and serialization—right at the endpoint level. In practical API development, mastering response models pays off both for self-documented code and robust, reliable interfaces. In this article, let’s dive deep…

FastAPI makes it delightfully simple to build high-performance APIs, but one common need in modern web development is to handle background work — like sending emails, updating statistics, or triggering other time-consuming tasks — without making the user wait. In this article, I’ll walk you through FastAPI’s built-in support for background tasks, how to use…

If you’re building an API with FastAPI, eventually you’ll need to address aspects like logging, authentication, request throttling, or response manipulation—all of which often span multiple routes. Rather than cluttering your endpoints or dependencies, FastAPI middleware lets you inject logic that acts before and after every request. In this article, I’ll show you how to…

When building robust APIs with FastAPI, effective testing isn’t just about hitting endpoints; it’s about ensuring that all the components—especially dependencies—work as expected. FastAPI’s dependency injection system is incredibly powerful, but understanding how to write focused, maintainable tests for them can be a game-changer. In this article, I’ll walk through strategies for testing FastAPI dependencies—both…

Versioning your API is crucial for maintaining backward compatibility as your application evolves. FastAPI makes API versioning straightforward, and with some attention to your project structure, you can maximize reusability and flexibility for future iterations. Why Version Your API? API versioning allows you to make breaking changes to your endpoints while ensuring existing clients are…

As FastAPI projects grow, code organization and reusability become increasingly important. While FastAPI’s dependency injection system is very flexible, you’ve probably noticed that many dependencies are simple functions. But did you know you can write dependency classes, too? In this article, I’ll show you how and why to use classes as dependencies for cleaner, testable,…

As a backend web developer working extensively with FastAPI, one of the nuances I often encounter is handling path parameters with precision. While FastAPI provides intuitive syntax for defining routes, leveraging its advanced parameter options can make your APIs more robust, maintainable, and user-friendly. In this article, I’ll share practical tips for fine-tuning path parameters…