Domain Driven Design is a process carried out by the development teams, in collaboration with Domain Experts, who represent the business.
Domain Experts, or DEs, are those within the business that be considered to be the most knowledgable about the business model. The DE should be closely involved with the development teams, and considered a part of the application development team.
The Domain Experts are the greatest source of the Ubiquitous Language.
See also:
Blog post: Blogged The Ubiquitous Language
Blog post: Blogged What Kind of Applications Is It Suited To
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