1. A computer network system for workflow-based data processing, in particular in connection with a computer-aided credit decision, wherein as part of the workflow a plurality of display pages are provided interactively using workflow control commands, with the computer network system comprising: a user terminal with a user interface that displays the plurality of display pages related to the computer-aided credit decision and that receives input of user data and workflow control commands; and one or more server systems comprising: one or more sourcing systems configured to access sourcing databases that contain sourcing data related to the computer-aided credit decision and at least one cache database into which the user data and a selected extract from the sourcing data are loaded; one or more service systems with services for performing data processing steps on the basis of data sourced from the cache database, and a mechanism comprising computer executable instructions stored in a memory of the computer network system configured to invoke, in response to the activation of at least one of the workflow control commands associated with a given display page of the plurality of pages displayed at the user terminal, at least one of the one or more services and the display of a new display page of the plurality of pages at the user terminal, wherein at least one of the services is invoked asynchronously with respect to the display of the new display page such that the new display page is displayed before the termination of the at least one invoked service if the setup of the new display page of the plurality of pages is independent of a result of the at least one invoked service.