Abstract: An example multi-tiered cloud application topology modeling tool is provided that facilitates receiving metadata associated with a widget, the widget being expressive of an interface representing a base class of a topology element in a cloud application topology, the topology element being classified in one of a plurality of tiers of cloud application topology, adding an instance of the widget to the cloud application topology, enforcing rules described by the metadata that specify behavioral constraints on the widget in a context of the cloud application topology across the plurality of tiers, and modifying the cloud application topology according to the rules without human intervention, the modified topology being rendered on a canvas of a user interface of the cloud application topology modeling tool. In specific embodiments, the cloud application topology on the canvas is converted to a stack blueprint that can be executed to instantiate the topology.