Cloud-based deployment using templates

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for selection of ranked configurations. In one aspect, a method includes providing a plurality of class definitions for selection, each class definition modeling a respective data or functional component of a cloud-based environment using a group of configurable class parameters, each class definition supporting instantiation and inheritance of the class definition in a configuration specification for a cloud-based deployment; deriving respective performance metrics associated with each of the plurality of class definitions based on aggregated performance of multiple cloud-based deployments, wherein the multiple cloud-based deployments had been carried out according to respective configuration specifications that require instantiation of the class definition or a new class definition derived from the class definition; and utilizing the respective performance metrics associated with each of the plurality of class definitions in ranking the plurality of class definitions.