Professional JavaScript (Node.js): Advanced Techniques

This book is not another introduction to JavaScript syntax. It is a deep dive into professional Node.js development for those who already write code confidently and want to move to the next level. "Professional JavaScript (Node.js): Advanced Techniques" is a practical guide to building high-load, fault-tolerant, and high-performance server-side applications.

What you will learn from the book:

• Event Loop Architecture and Asynchrony: Detailed breakdown of event loop phases, microtasks and macrotasks, working with async/await at the level of promises and callbacks. You will learn to predict code behavior and avoid "hellish" scenarios.
• Worker Threads and Child Processes: How to effectively use multithreading in Node.js, distribute load across CPU cores, and build parallel computations without blocking the main thread.
• Clustering and Load Balancing: Setting up production clusters, managing child processes, graceful shutdown, and zero-downtime deployment.
• Memory and Performance Optimization: Profiling memory leaks, working with buffers and streams, configuring V8 and the garbage collector for maximum speed.
• Advanced Testing: Integration tests, mocking external services, load testing, and writing your own test utilities.
• Microservice Architecture: Design, communication via message queues (RabbitMQ/Redis), error handling, and monitoring in distributed systems.
• Core-Level Security: Protection against DoS attacks, input validation, working with cryptography, and secure secret storage.

Who this book is for:

• Middle and Senior JavaScript developers who want to deepen their Node.js knowledge.
• Backend engineers transitioning from other languages (PHP, Python, Java) to Node.js.
• Architects designing microservice systems.
• Developers preparing for technical interviews for Senior Node.js Developer positions.

The book contains many real-world cases, ready-to-use code snippets, and exercises for independent work. You will not just read theory — you will learn to write code that withstands thousands of requests per second and runs for years without failures. Examples are based on current versions of Node.js (18+ LTS) and popular libraries (Express, Fastify, PM2, Bull).

After reading, you will be able to confidently solve optimization, debugging, and scaling tasks that stump 90% of developers. Become the specialist people turn to for solving the most complex problems in Node.js.