C++ API Development: Creating High-Performance Libraries and Services

The book "C++ API Development" is a comprehensive guide to creating modern network interfaces and services in the C++ language. In the era of microservice architecture and high-load systems, C++ remains the unparalleled choice when maximum performance, minimal memory consumption, and predictable latency are required. This book will take you from the basics of API design to the industrial deployment of ready-made solutions.

What is this book about?

The author systematically covers all stages of API development in C++:

• Interface Design — principles of REST, GraphQL, and gRPC, contracts, and versioning.
• HTTP/HTTPS Servers — working with Boost.Beast and non-blocking I/O (ASIO).
• Data Serialization — Protocol Buffers, JSON (Nlohmann/json), MessagePack.
• Databases and Caching — integration with PostgreSQL (libpqxx), Redis (hiredis), in-memory caching.
• Asynchrony and Concurrency — C++20 coroutines, thread pools, lock-free structures.
• Security — JWT, OAuth2, CSRF protection, rate limiting, TLS.
• Testing and Documentation — unit tests (Google Test), integration testing, OpenAPI/Swagger.
• Deployment and Monitoring — Docker, Kubernetes, Prometheus metrics, logging (spdlog).

Who is this book for?

• Backend developers in C++ looking to transition from utilities to network services.
• Engineers working with high-load systems (FinTech, AdTech, IoT).
• Python/Go developers who want to learn C++ for performance-critical components.
• Students and postgraduates studying system programming.

What will you learn?

• How to design an API that is convenient for clients and efficient on the server.
• Implementing a REST server from scratch using pure C++ and Boost.Beast.
• Creating gRPC services with bidirectional streaming data.
• Performance optimization: from profiling to reducing latency to microseconds.
• Handling thousands of concurrent connections with minimal overhead.
• Practical techniques for working with C++20 coroutines for asynchronous code.

The book contains dozens of code examples ready for compilation and execution. Each chapter concludes with a practical assignment and review questions. This is not a reference manual, but a working tool — after reading it, you will be able to independently develop an API for a real-time service, whether it be an order book, a chat, or a telemetry system.

To read this book, a solid knowledge of C++ (classes, templates, STL) and a basic understanding of network protocols are sufficient. The book is oriented towards the C++17 and C++20 standards, and all examples have been tested under GCC and Clang.