Domain-Driven Design (DDD)
category: Architecture
tags: ddd, java, design, microservices, kubernetes
Main Topic 1
Domain-Driven Design (DDD) is an approach to software development that focuses on modeling software based on the business domain, using rich, behavior-focused models.
Subtopic A: What It Is
- Uses bounded contexts to divide complex systems
- Rich domain models with entities, value objects, and aggregates
- Collaboration between developers and domain experts
Subtopic B: Why Use It
- Aligns code with real business logic
- Helps manage complexity
- Encourages strategic design decisions
Subtopic C: When To Use It
- Complex business domains
- Multiple subdomains and teams
- Systems needing long-term evolution
Main Topic 2
Code Example (Java Domain Model)
public class Invoice {
private List<LineItem> items;
public BigDecimal getTotal() {
return items.stream().map(LineItem::getAmount).reduce(BigDecimal.ZERO, BigDecimal::add);
}
}
Infra Tip (Kubernetes)
Use namespaces or Helm charts to separate bounded contexts in microservices deployments.
Key Concepts Summary
- Focus on business logic and models
- Uses Ubiquitous Language between tech and business
- Breaks systems into bounded contexts
Best Practices / Tips
- Work closely with domain experts
- Use layered architecture within each bounded context
- Combine with event-driven or microservices architecture
Common Issues / Troubleshooting
Problem 1: Overengineering
- Cause: DDD applied to simple domains
- Solution: Use tactical patterns only where needed
Problem 2: Poor context boundaries
- Cause: Miscommunication or unclear scope
- Solution: Use Event Storming to clarify models
References / Further Reading
- https://domainlanguage.com/ddd/
- https://www.dddcommunity.org/
Last updated: 2025-08-26 20:00 UTC