Kurly Shares Experience Transitioning to DDD-Based MSA, Emphasizing Loose Coupling and High Cohesion Principles

A Kurly engineer shared their experience applying the core design principles of DDD (Domain-Driven Development) during the process of transitioning a commerce platform to MSA (Micro Service Architecture). DDD is a development methodology proposed by Eric Evans in 2003, and it provides Loose Coupling and High Cohesion, which are essential concepts for implementing MSA.

The Importance of Domain Division

The success of MSA design hinges on how appropriately domains are divided. Loose Coupling must be maintained between domains, while High Cohesion must be secured within domains. Improper domain division can increase system complexity or cause unexpected issues, so setting domain boundaries that properly reflect business problems is the top priority.

3 Key Benefits of MSA

The benefits of MSA, interpreted from a DDD perspective, are as follows.

• Strong Module Boundaries: Clear module boundaries ensure that changes only affect microservices within a specific domain.
• Independent Deployment: Design that considers dependency relationships facilitates independent deployment of microservices, which serves as the foundation for CI/CD automation.
• Technology Diversity: While maintaining similar technology stacks within a domain, diverse technologies optimized for solving problems can be introduced between domains. However, excessive technology diversity can lead to complexity, so it should be adjusted according to organizational maturity.