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

The book "API Development in C# (.NET)" is a comprehensive guide to building modern, scalable, and secure web services on the Microsoft .NET platform. Unlike academic textbooks, this book is built on real-world cases and best practices used in production development.

What is this book about?

You will go through the complete journey from API architecture design to deployment in the cloud. Each chapter contains practical examples, ready-to-use code snippets, and explanations of architectural decisions. The main focus is on:

• Building RESTful APIs using ASP.NET Core 8/9
• Working with Entity Framework Core and Dapper for data access
• Implementing authentication (JWT, OAuth2, IdentityServer)
• Data validation, error handling, and logging
• API documentation via Swagger/OpenAPI
• Testing (unit, integration, load testing)
• Deployment to Docker, Azure, AWS, and Linux servers

Who is this book for?

• Beginner C# developers who want to learn backend development
• Middle-level developers looking to systematize their API knowledge
• Full-stack developers transitioning to the .NET ecosystem
• Team leads seeking practical architectural recommendations

What will you learn?

• How to properly design endpoints and version APIs
• Performance optimization: caching, pagination, asynchrony
• Patterns: Repository, CQRS, Mediator, Unit of Work
• Handling multithreading and concurrent access
• Integration with external services and microservice architecture
• Monitoring and debugging: Application Insights, Serilog, Grafana

The book is written in a lively style with minimal fluff. At the end of each chapter, there is a self-check checklist and a practical assignment. All code examples are available in a GitHub repository and tested on the latest .NET versions.

This is not just a textbook — it is a desk reference for every .NET developer who wants to write APIs they can be proud to show to colleagues and clients.