The Pehapkari.cz blog has posted the latest article in their "Domain-Driven Design" series of posts covering the focus on the "domain" when developing an application rather than just features. In this latest tutorial, they cover services and factories to help with the encapsulation of functionality...and why they shouldn't be used.

This article is a reaction to readers’ confusion about services. We'll cover a domain service and domain factory in this article and when to use them and when not to.

Domain-driven design is about the domain. Domain services and domain factories do not exist in the domain. In general, we shouldn't use them. They are artificial constructions and this causes a lot of problems with code understanding, maintainability and also a divergence between the domain, the model, and the code.

The article continues the use of the e-commerce example when talking about the ideas of services and factories in the domain. It provides some basic examples (flow diagrams included) and the reasoning why they should not be used and what they could be replaced with.