The infrastructure layer comprises the external systems. The CarSytem API provides static car data (e.g., vin, brand) and dynamic data (e.g., access to the trunk) to the Domain API.
The domain logic layer comprises the Domain APIs. The development of the Domain API is strongly influenced by Domain-Driven Design (DDD).
The Domain API Car unifies a subset of the car data that is domain-specific. An Application Microservice API should use the Domain API to retrieve manufacturer-independent data. Because when new car manufacturers are integrated, the Application API does not have to be modified as the Domain API endpoints will remain unchanged.
The application logic layer contains the Application Microservice APIs which are derived from the capabilities. The Application Microservice API FleetManagement implements the use cases regarding the management of the fleet with the information provided by Car. The Application Microservice API RentalManagement implements the use cases regarding the management of rentals with the information provided by Car.
The presentation layer contains the user interface UI-CCSAppWeb.