How do you break down a monolithic application into microservices?

Breaking down a monolithic application into microservices is an architectural transformation process aimed at enhancing the agility, scalability, and maintainability of the application. A monolithic application integrates all functions into a single codebase, which is easy to initially deploy but difficult to adapt to changes; microservices, on the other hand, are decomposed into independently deployable small services, each focusing on a single business capability. This decomposition is particularly important in large enterprise systems and high-concurrency scenarios, supporting rapid iteration and cloud-native environment deployment.

The decomposition involves core principles such as service autonomy, Domain-Driven Design (DDD), and API communication. It is necessary to identify business subdomains in the monolith (such as user authentication or order processing), define clear boundaries, and refactor them into independent service units. In practical applications, containerization tools and Kubernetes are used to deploy microservices, improving system resilience, observability, promoting DevOps culture, and reducing the impact of single points of failure.

Implementation steps: First, evaluate the monolithic structure and identify module dependencies; second, divide service boundaries (using DDD aggregates); then, gradually extract services and implement API interfaces; finally, test and deploy microservices individually. Typical scenarios include the splitting of e-commerce orders. Business values include faster release cycles, independent scaling capabilities, and reduced overall maintenance costs.