Methods and systems are described for creating and/or processing a definition for a dashboard with manually input code and user selections in a graphical user interface. In some implementations, user interface elements are displayed and selections from a user accepted. Responsive to the selections, definitions for one or more visualizations and datasources are automatically generated and displayed in a user interface element that accepts manually input customizations and code from the user. The resulting combination of code and definitions is stored as a definition for the dashboard, which when processed will transform data received from the at least one of the datasources, combine the transformed data with data from another of the datasources, and cause the display of a visualization based on the combined data.