Backend Overview

The backend is structured into the following levels:

• XYZController: receives requests through the API for endpoint /xyz
• Mapper: maps from/to DTOs
• XYZService: the business service for XYZ
• ValidationService: validates business constraints
• PersistenceService: provides access to the database and any operations that need the database
• Repository: interface to the database

A hypothetical request is plotted in the diagram below. Note that some calls are optional.