DDD - Dependencies between domain model, services and repositories

Question

Just wanted to know how others have layered their architecture. Say I have my layers as follows:

Domain Layer
--Product
--ProductService (Should the imp go

Answer 1

To your last point, services in DDD are a place to put what I describe as "awkward" logic. If you have some type of logic or work flow that has dependencies on other entities this is the type of logic that usually doesn't "fit" inside a domain object itself. Example: If I have a method on my business object to perform some type of validation, the service class might execute this method (still keeping the actual validation logic related to the entity inside its class)

Another really good example I always mention is the funds transfer method. You wouldn't have an account object transfer from one object to another, but instead you would have a service that takes the "to" account and the "from" account. Then inside the service you would invoke the withdrawal method on your "from" account and the deposit method on your "to" account. If you tried to put this inside the account entity itself it would feel awkward.

A great podcast that talks in depth about this very topic can be found here. David Laribee does a really good job explaining now only the "how" but the "why" of DDD.