JavaScript (Node.js) Application Architecture

This book is not just a collection of Node.js recipes, but a deep dive into the architectural principles of building modern server-side applications in JavaScript. The author, drawing on many years of experience developing high-load systems, consistently guides the reader from simple monolithic solutions to complex, distributed, and fault-tolerant systems.

You will learn how to properly organize code so that the application is easy to scale, test, and maintain. Special attention is paid to choosing an architectural style: when a monolith is sufficient, and when it's time to move to microservices, and how to make this transition painless.

Who this book is for

• Node.js backend developers who want to go beyond simple CRUD applications
• Team Leads and architects looking for proven patterns for designing complex systems
• Developers transitioning from other languages (Python, Java, C#) to Node.js and wanting to understand its strengths
• Anyone who has faced problems with scaling and maintaining "spaghetti code" in JavaScript

What you will learn

• Core architectural patterns: layered architecture, hexagonal architecture (Ports & Adapters), onion architecture
• Designing microservices on Node.js using RabbitMQ, Kafka, and gRPC
• CQRS (Command Query Responsibility Segregation) and Event Sourcing patterns for data handling
• Organizing testing: from unit tests to integration and E2E tests
• Error handling, logging, and monitoring in distributed systems
• Security: authentication, authorization, protection against common vulnerabilities
• Performance optimization and memory management in Node.js

The book contains many practical examples and ready-made architectural templates that can be immediately applied in real projects. All examples are accompanied by detailed comments and explanations of "why it works this way."

A special feature of the publication is its emphasis on evolutionary design. You will learn not just to copy ready-made solutions, but to make informed architectural decisions based on the context and requirements of your project. This is not a reference book, but a practical guide that will help you become an architect, not just a coder.