1. A system, comprising: one or more processors; memory that includes a plurality of computer-executable components that are executable by the one or more processors, comprising: an extensibility library that includes one or more transformation directives, the one or more transformation directive specifying a business semantic preserving transform that transforms at least one source application component of a source application into one or more transformed application components of a transformed application, the business semantic preserving transform as specified by the one or more transformation directives of the extensibility library causes an execution of transformed code of the one or more transformed application components of the transformed application in a new execution scenario to produce an identical semantic effect as an execution of source code of the at least one source application component of the source application in an old execution scenario; and an transformation application that transforms the source application into the transformed application using the business semantic preserving transform, the business semantic preserving transform changing one or more original architectural classes of the source application into one or more transformed architectural classes of the transformed application, the one or more original architectural classes having at least one architectural difference from the one or more transformed architectural classes.