I don't think saying ORMs are an implementation detail is useful. DDD is a design and implementation strategy. It is telling you how to structure and build your

I don't think saying ORMs are an implementation detail is useful. DDD is a design and implementation strategy. It is telling you how to structure and build your application. For example, DDD says you should have entities and repositories. Well, that's an ORM: you have models (entities) and some kind of querying facility (maybe a fluent API, maybe a parameterized API, but whatever, it's a repo). Realistically, when using an OO language w/ an SQL database, there's realistically no other way to do this. You'll either use an existing ORM, or you'll end up building a weird, custom ORM. In fact, some of my frustration with DDD is that because it uses so much new language to refer to existing concepts, techniques, and technologies, it obfuscates the fact that you're probably already using DDD in some significant measure. Like are you using Spring, Rails, or Django? You're probably more than 3/4 the way to DDD.