Rich Domain Model
A Rich Domain Model is a software design pattern in object-oriented programming where domain objects (entities) contain both data and behavior, encapsulating business logic within the model itself rather than in separate service layers. It emphasizes modeling real-world business concepts with complex rules and relationships directly in the code, making the domain layer intelligent and self-contained. This approach contrasts with anemic domain models, where objects are primarily data containers with logic placed elsewhere.
Developers should use a Rich Domain Model when building complex business applications where domain logic is intricate and central to the system, such as in enterprise software, financial systems, or e-commerce platforms. It improves maintainability by keeping related logic together, enhances testability through encapsulated behavior, and makes the code more expressive of the business domain, reducing the risk of logic duplication and inconsistencies. This pattern is particularly valuable in Domain-Driven Design (DDD) contexts to model bounded contexts effectively.