The article defines a clear rule for placing methods in DDD aggregates: a method belongs inside the domain object only when it can operate solely on data owned by that object, illustrated with order status and marketing activity examples.
The article explains why traditional three‑layer architectures let business logic bloat inside services, demonstrates the pitfalls of anemic domain models with a 7,000‑line SalaryService example, and shows how DDD’s rich domain model restores rule ownership and maintainability.
This article introduces the fundamentals of Domain‑Driven Design (DDD), explains key concepts such as rich domain models, entities, value objects, aggregates, repositories, adapters, and application orchestration, and demonstrates their implementation through comprehensive Java code examples and a complete project structure diagram.
This article explores why software systems inevitably become more entropic and complex, draws parallels with physical entropy and the Constructal Law, identifies sources of uncertainty, scale, and cognitive cost, and presents practical approaches such as isolating core kernels, adopting Domain‑Driven Design, and applying Clean Code principles to keep systems maintainable.
