Domain-Driven Design for Java

Tactical DDD patterns for rich, behavior-driven domain models.

vs hexagonal-java: This skill focuses on domain modeling — Value Objects, Entities, Aggregates, Domain Events, and Ubiquitous Language. Use hexagonal-java when you need package structure and dependency direction — how to organize ports, adapters, and use case classes in Spring Boot.

When to Activate

• Modeling a new domain concept (what is this thing? entity or value object?)
• Deciding whether logic belongs in domain, use case, or adapter
• Identifying aggregate boundaries and consistency rules
• Designing domain events and their dispatch
• Reviewing for anemic domain model (data containers with no behavior)
• Naming classes, methods, and packages (ubiquitous language)
• Planning a multi-service system with bounded contexts

Building Block 1: Value Objects