An application is developed and built through a development platform. The application provides a user interface to serve user requests. The application provides expanded set of data entities stored at a back-end application. The application communicates with the development platform to request data from the back-end application. The development platform communicates with the back-end application through sending and receiving communication messages with a connection server. The expand data services are implemented on the connection server to access and provide data associated with a requested data entity. The provided data expand services are also serving delta data requests associated with updates on the back-end application. The delta data is related to a previous data download request at the back-end application. The provided data expand services, which support delta data querying, are utilized during initial data loading of the application.