Domain-driven design

Domain-driven design (DDD) is a major software design approach, focusing on modeling software to match a domain according to input from that domain's experts.

Under domain-driven design, the structure and language of software code (class names, class methods, class variables) should match the business domain. For example: if software processes loan applications, it might have classes like "loan application", "customers", and methods such as "accept offer" and "withdraw".

Domain-driven design is predicated on the following goals:

• placing the project's primary focus on the core domain and domain logic;
• basing complex designs on a model of the domain;
• initiating a creative collaboration between technical and domain experts to iteratively refine a conceptual model that addresses particular domain problems.

Critics of domain-driven design argue that developers must typically implement a great deal of isolation and encapsulation to maintain the model as a pure and helpful construct. While domain-driven design provides benefits such as maintainability, Microsoft recommends it only for complex domains where the model provides clear benefits in formulating a common understanding of the domain.

The term was coined by Eric Evans in his book of the same title published in 2003.