What is domain-driven design?
Domain-driven design builds complex software around carefully modeled business concepts and rules.
How it works and where it is used
Developers and domain experts create a shared language. Bounded contexts explain why the same word may differ in sales and accounting. Entities, value objects and aggregates are useful tactical patterns, but memorizing them cannot replace understanding strategic boundaries. Models are tested against real workflows.
Limits, safety and selection criteria
Not every CRUD application needs elaborate modeling. The approach pays off where rules and stakeholders are complex. Service boundaries may follow contexts but need not map one-to-one. Conversation and iterative code expose mistaken assumptions. The word “customer” may mean buyer in sales, support requester in service and debtor in accounting. Forcing all meanings into one huge model creates surprising breakage. A bounded context states where a term and its rules apply. Translation layers can connect contexts without requiring identical data models. Discussing concrete cases with domain experts often reveals misunderstandings earlier than drawing a diagram in isolation. The goal is a code model that changes in step with business understanding, not merely a new set of class names.