API Engineering with Python and FastAPI

Reactive Publishing

Modern API development requires more than writing endpoints. It demands clear service design, reliable data handling, authentication patterns, testing discipline, deployment awareness, and an understanding of how backend systems operate beyond the local development environment.

API Engineering with Python and FastAPI is a practical guide to building backend services using Python and FastAPI, with a focus on structure, maintainability, and real-world engineering workflows. The book introduces the core concepts behind API design, request handling, data validation, authentication, database integration, testing, documentation, and deployment-oriented development.

Inside, readers will explore how FastAPI supports modern backend development through type hints, dependency injection, asynchronous programming, automatic documentation, and structured application design. The book also covers common backend concerns such as routing, schemas, middleware, error handling, security practices, environment configuration, logging, monitoring concepts, and service organization.

Designed for developers who want to move beyond basic API tutorials, this book emphasizes practical engineering judgment: how to structure projects, separate concerns, manage configuration, test endpoints, document services, and prepare applications for more robust deployment workflows.

Topics include:

• REST API design principles
• FastAPI application structure
• Pydantic models and data validation
• Authentication and authorization patterns
• Database integration with Python
• Async workflows and background tasks
• Middleware, exception handling, and logging
• Testing APIs and backend services
• OpenAPI documentation
• Deployment workflows and operational considerations

Whether you are building internal tools, SaaS backends, data services, automation platforms, or application APIs, API Engineering with Python and FastAPI provides a structured foundation for designing backend services with clarity, reliability, and long-term maintainability.