C++ API Development: From Fundamentals to Industrial Solutions

The book "API Development in C++" is a comprehensive practical guide that will take you from the fundamental principles of building application programming interfaces to creating industrial microservice solutions. The author, Alexey Vetrov, a senior engineer with 12 years of experience in high-load systems, shares proven patterns and techniques that will help you write reliable, scalable, and performant code.

This edition is aimed at developers who are confident in C++ syntax (Junior/Middle level). If you want to move from writing utilities to creating network services that can handle thousands of requests per second, this book is for you. It doesn't overload you with theory but immediately immerses you in practice: you will start writing code from the first chapter.

What you will learn and master:

• Basics of working with Boost.Asio and C++ coroutines for asynchronous I/O
• Designing RESTful APIs using the Pistache and Crow libraries
• Implementing gRPC services with protobuf and client/server generation
• Developing WebSocket servers for real-time communications
• Error handling, logging, metrics, and monitoring (Prometheus + OpenTelemetry)
• API testing: unit tests, integration tests, load testing (gtest, benchmark)
• Performance optimization: memory pool, zero-copy, connection pooling
• Security: authentication (JWT, OAuth2), encryption (TLS 1.3), DDoS protection
• Containerization and deployment (Docker, Kubernetes, CI/CD pipelines)

The book contains over 20 complete examples available in the repository. Each example is accompanied by a detailed analysis of architectural decisions and an explanation of why a particular approach was chosen. Special attention is paid to comparing the performance of different frameworks and protocols (REST vs gRPC vs WebSocket) in real-world scenarios.

Key features of the edition:

• Focus on modern C++17/20 standards (coroutines, concepts, ranges)
• Industrial patterns: CRTP, PIMPL, RAII, factories, object pools
• Ready-made project templates for a quick start
• Tips on refactoring legacy code and migrating to new standards

This book will become your desktop reference when developing any network service in C++. Whether you are creating a backend for a mobile application, a high-load game server, or a microservice for a financial system, you will find ready-made solutions and best practices here. Start writing APIs that never let you down!