In this post, Manuel Felício starts with
a simple business domain model and then creates a domain layer around that model.
In this example our app will be a web application for a company that sells products and that can be used by its customers to fulfill orders and its employees to process them. These orders have details which consist of products and quantities. Each product can have a product category. When a customer submits an order fulfillment, an employee of the company may process that order to prepare the items for shipping.
You can find the previous parts of the series here: