Storing data models together

A system and method for modeling cross system content between a hub and one or more backend systems is disclosed. Model content of one or more data models is stored in a model stack defined in a storage. The model content of each data model includes model metadata representing a model of a backend system. Cross model content is stored in a cross model stack. The cross model content includes reference metadata representing one or more references associated with a data model of one backend system and that reference a data model of another backend system. Central cross model content is stored in a central cross model stack. The central cross model content includes one or more cross elements that do not belong to the model content of any of the data models, and that establish a connection between two data models of different backend systems.