The article delves into four design patterns in Node.js, illustrating their practical applications and benefits. The module pattern focuses on organizing code into modules to control visibility and prevent global namespace pollution, ensuring a cleaner and more organized codebase. The adapter pattern allows for the adaptation of one API to another, enabling compatibility with changing APIs without affecting existing code. The decorator pattern enhances an object’s functionality dynamically at runtime, promoting flexible and reusable code without altering the original structure. Lastly, the command pattern encapsulates complex behaviors into simple modules with a unified API, facilitating scalability and ease of modification. These patterns collectively aim to improve code quality, maintainability, and scalability in software development.