domain-modeling

Domain modeling uses entities and aggregates to encapsulate business rules and ensure data consistency. Identify aggregate roots to represent core business concepts, define entities within those aggregates, and enforce invariants so your model accurately reflects business logic and remains maintainable as complexity grows.

Value objects represent descriptive aspects of your domain—like Money, Address, or Status—and enforce immutability and type safety. Use them for domain concepts that lack identity and whose equality depends on their attributes, reducing bugs and making business intent explicit in code.

Domain events capture significant business occurrences and enable communication between aggregates and services without tight coupling. When an important action happens—like an Order placed or Account created—publish the event so other parts of your system react asynchronously and independently.

Encode business rules as invariants within aggregates and entities using BR-XXX format identifiers. Define role-based permission structures and document them alongside entity definitions so rules are enforced at the domain layer, preventing invalid state and making governance auditable.

Ubiquitous language creates a shared vocabulary between domain experts and developers, ensuring consistent understanding of business concepts. This reduces translation errors, aligns code structure with business thinking, and makes domain models self-documenting and easier to evolve.

Yes. Domain modeling is well-suited for complex financial systems where precise business rule enforcement matters. Define aggregates like Trade, Account, and Order; use value objects for Money and quantities; and capture domain events for settlement and reconciliation to ensure correctness and auditability.