API Development in ASP.NET Core Web API is a practical, project-driven guide designed to help developers build, test, and deploy fully functional RESTful APIs using modern architectural patterns. This book adopts a hands-on approach, focusing on real-world implementation rather than just theory. It is ideal for students, backend developers, software engineers, and professionals who want to master API development using ASP.NET Core.

The book is structured into multiple parts, each covering a critical dimension of API development—from understanding RESTful services to implementing APIs using layered and Onion Architecture, followed by testing and deployment on Azure and production servers. By the end of this book, readers will have built complete, production-ready API projects with structured architecture and deployment strategies.

Why You Should Learn API Development in ASP.NET Core

RESTful Web APIs are the backbone of modern web, mobile, and cloud applications. Learning ASP.NET Core Web API enables developers to build scalable, secure, and high-performance backend services.

Strong API development skills are essential for microservices, cloud-native applications, enterprise systems, and technical interviews. This book provides both architectural understanding and practical execution.

What Makes This Book Different?

This book follows a complete practical lifecycle: development, architecture, testing, and deployment. It provides real GitHub-based projects and demonstrates structured architectural patterns. The book emphasizes:

• Practical API implementation using ASP.NET Core

• RESTful Web Services fundamentals

• Three-Tier and Onion Architecture implementation

• Hands-on API testing using Swagger and Postman

• Deployment on Azure Cloud and hosting servers

Who Should Read This Book?

This book is ideal for:

• ASP.NET Core developers

• Backend and API developers

• Software engineering students

• Developers preparing for interviews

• Professionals building enterprise APIs

Chapter Overview

Chapter 1: API Development Using ASP.NET Core

This chapter introduces RESTful Web Services and explains why they are essential in modern application development. Readers learn how to implement a complete API project using ASP.NET Core with practical examples and GitHub reference.

Chapter 2: API Development Using Three-Tier Architecture

This chapter explains the Three-Tier Architecture and its importance in structured application design. Readers learn how to architect an ASP.NET Core Web API using presentation, business, and data access layers.

Chapter 3: API Development Using Onion Architecture

This chapter introduces Onion Architecture and its benefits for maintainability and scalability. Readers implement a fully structured API project following clean separation of concerns.

Chapter 4: API Testing Using Swagger

This chapter focuses on API testing using Swagger within ASP.NET Core. Readers learn how to test GET, POST, PUT, DELETE, and UPDATE endpoints efficiently through interactive documentation.

Chapter 5: API Testing Using Postman

This chapter explains API testing using Postman for real-world validation. Readers learn how to send requests, analyze responses, and validate endpoint behavior step by step.

Chapter 6: Application Deployment on Azure Cloud

This chapter covers deploying an ASP.NET Core Web API to Azure Cloud. Readers learn how to configure Azure App Services, deploy using Visual Studio, and verify output on live Azure websites.

Chapter 7: Application Deployment on Hosting Server

The final chapter explains deploying the application to a production hosting server. Readers learn server configuration, deployment steps, and best practices for running APIs in live environments.

API Development in ASP.NET Core Web API equips readers with the practical knowledge, architectural understanding, and deployment skills required to build and maintain production-ready RESTful APIs with confidence.