SOA vs Microservices: Their Contrasts, Differences, and Key Features

Enterprise software applications have traditionally been monolithic, creating challenges in scalability and maintenance, leading to the emergence of Service-Oriented Architecture (SOA) in the late 1990s and later microservices around 2011. Both SOA and microservices aim to address the limitations of monolithic architectures by enabling applications to be composed of smaller, more manageable components. SOA focuses on reusability and integration through loosely coupled services that communicate over a network, often using an Enterprise Service Bus (ESB), which can become a single point of failure. In contrast, microservices prioritize independence and flexibility, with components that are often deployed in containers and communicate using lightweight, language-agnostic APIs, making them more suitable for cloud-native applications. The two architectures differ in their approach to data governance, communication protocols, service granularity, and deployment speed. While SOA supports enterprise-wide scalability and component sharing, microservices offer high cohesion and scalability for specific applications, representing an evolution from SOA's foundational principles.