This is my specific situation:
I am following DDD and Event sourcing to implement my application (using C#). I have a Domain layer that contains Aggregates' implementation. I write unit tests for this layer to cover my business logic.
Consider Employee aggregate that contains a field which is named PartyId. I have a specification that says, If the Party doesn't exist, I will receive an error with code 'NotFoundParty-01'.
For more details, Party is defined in another Bounded Context and Its Id will be used in Employee. I am having two different kinds of databases. one for reading(projection) and another for writing(event-store).
Now, I have a general question. Checking this kind of existence is the Domain concern or any other layers? According to the specification, this logic should be in the Domain layer or it can be on the others too?
Is it possible that the analysis guy thought in a technical way? because existing of an Aggregate is not that much business-related.