1. A method comprising: receiving, in a graphical user interface area, first inputs specifying drag-and-drop operations with respect to icons representing documents, the drag-and-drop operations indicating that the documents are to be added to a workflow represented by the graphical user interface area; depicting the documents within the graphical user interface area in a particular order, wherein the particular order reflects dependencies between the documents, the particular order indicating at least that processing of a second document of the documents is dependent upon a first document output of a first document of the documents; processing the workflow to generate a first workflow output for the workflow, wherein processing the workflow comprises at least iteratively generating outputs for each of the documents, in accordance with the particular order, the outputs including the first document output and a second document output for the second document; wherein generating the first document output comprises executing instructions within the first document configured to cause deriving a data set from a data source external to the first document; wherein generating the second document output comprises executing instructions within the second document configured to cause generating one or more graphs based on the first document output; reprocessing the workflow to generate a second workflow output for the workflow, wherein the second workflow output differs from the first workflow output as a result of a change in the first document output; wherein the method is performed by one or more computing devices.