API Development in C# (.NET): Creating Modern Web Services

This book is your reliable guide to the world of creating modern web services on the .NET platform. Whether you are starting your journey in backend development or already have experience with C#, you will find structured knowledge and ready-made solutions for designing, implementing, and documenting APIs.

What is this book about?
The publication covers the full API development cycle: from architecture design to deploying the finished solution. You will learn:

• The basics of REST and the principles of creating resource-oriented services.
• Working with the ASP.NET Core framework: configuring routing, middleware, filters, and error handling.
• Connecting and configuring databases (Entity Framework Core, Dapper).
• Authentication and authorization: JWT, Identity, OAuth 2.0.
• Documenting APIs with OpenAPI/Swagger.
• Testing (unit tests, integration tests) and debugging.
• Performance optimization, caching, versioning, and pagination.
• Deployment to cloud services (Azure, Docker) and CI/CD.

Who is this book for?
The book is intended for developers who are familiar with the basics of C# and want to systematize their knowledge of creating APIs. It will be useful both for junior specialists seeking to master a sought-after specialization and for middle-level developers looking to delve into best practices and advanced techniques.

What will you learn?
After reading the book, you will be able to confidently design RESTful APIs, choose the correct HTTP methods and status codes, efficiently handle requests, protect services from unauthorized access, and write clean, maintainable code. You will learn to integrate third-party services, work with WebSocket and SignalR for real-time communications, and automate testing and deployment processes.

Each chapter contains practical examples, diagrams, and code snippets that can be immediately applied in real projects. Special attention is given to common mistakes and ways to avoid them. At the end of the book, you will find a step-by-step guide to creating a full-fledged API for an online store — from the data model to documentation.

Why choose this book?
The author is a practicing developer with 10 years of experience creating high-load services in C#. The material is structured so that you can read the book sequentially or refer to specific chapters as a reference. All examples are compatible with the latest versions of .NET (6/7/8) and are current as of 2024.

Start creating professional APIs today — this book will be your reliable companion in the world of C# and .NET.