The evolution of web services from service-oriented architecture (SOA) to microservices has transformed how applications are built, with Express.js emerging as a standout choice for creating lightweight, efficient RESTful APIs. This shift allows developers to craft independent, scalable services that enhance flexibility and resilience, enabling teams to innovate rapidly and respond to changing business needs. By embracing key principles like the single responsibility principle and decentralized data management, organizations can streamline their code and improve system reliability. Moreover, effective communication between microservices—whether through synchronous methods like HTTP/REST or asynchronous approaches using message brokers like RabbitMQ and Kafka—ensures seamless interaction and robust performance. Ultimately, leveraging microservices and tools like Express.js empowers developers to create dynamic applications that thrive in today’s fast-paced digital landscape.