service-layer

A service layer in domain-driven design orchestrates business logic use cases and coordinates multiple domain entities. You need one when features require coordinating operations across multiple domain objects or external systems to ensure clean separation of concerns.

To orchestrate business logic without thick services, keep application services stateless and focused solely on use case coordination. Delegate actual business rule enforcement to the domain layer, ensuring thin services with rich domains and single responsibility.

Manage transaction boundaries by defining atomic boundaries within the service layer during business logic orchestration. This ensures data consistency when coordinating multiple domain operations, allowing steps to succeed atomically or be compensated for if they fail.

Yes, you can use a service layer to decouple application concerns from domain logic. It facilitates implementing use cases and handles translation between domain models and DTOs, keeping domain logic isolated from application orchestration.

The best way to structure this use case is within a service layer that orchestrates customer and order repositories. It coordinates updating customer information, processing the order, and sending confirmation email atomically or compensates for any failures.

You should avoid a service layer when business logic naturally fits within a single domain entity and requires no coordination across multiple objects or external systems. Overusing service layers leads to anemic domain models and unnecessary orchestration overhead.