The document serves as a comprehensive guide on building Node.js microservices architecture, emphasizing the importance of modular design for scalability and agility. It highlights the advantages of using Node.js, such as faster execution, flexibility, and ease of deployment, while also outlining a step-by-step process for creating microservices, including requirement research, database connections, route specification, and handling external API calls. The guide concludes by reinforcing the necessity of continuous evaluation and improvement as applications evolve.