Domain-driven design

Domain-driven design (DDD) is a software design approach that focuses on modeling software to match a domain according to input from that domain's experts. DDD is against the idea of having a single unified model; instead it divides a large system into bounded contexts, each of which have their own model. 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 layer; 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 name published in 2003.