A design tool for assembling component objects to form an object-based computer system application includes a declarative user input interface mechanism and a design engine. The declarative user input interface mechanism provides an input structure for the input of user declarations specifying operative interactions between component objects. The design engine automatically generates, in response to input user declarations, an application design definition modeling an application infrastructure for managing component object interactions. The design engine automatically generates, in response to input user declarations, a match between an application view field definition and a parameter of an associated component object operations. A runtime tool includes an application engine which is responsive to an application design definition and is operative at runtime automatically to create application view instances from respective application view definitions for managing runtime component object interactions for the applications.