8 NDepend Rules to Enforce Domain-Driven Design in .NET

Disclosure: NDepend provided a complimentary 1-year license for me to test the software featured in this article. When you first start implementing Domain-Driven Design (DDD) in your project, you invest considerable effort in clearly defining Bounded Contexts, identifying Aggregates, and ensuring your abstraction layers are properly defined. Fast-forward six months, however, and you'll likely find your initial structure has degraded. A domain service now calls an ORM directly. Value objects have become mutable. While code reviews catch obvious violations, subtle architectural drift slips through the cracks when reviewers focus on business logic rather than structural rules. These small violations compound, eventually turning your DDD project into a Big Ball of Mud unless you actively prevent it. The solution is to implement fitness functions, which are automated checks that detect when new code deviates from your DDD principles. One tool that enables this is NDepend, a powerful .NET st