Methods, systems, frameworks, and software products for building well-defined software modules through aggregation of other similar modules at any depth. The system can provide visual methods of aggregation and nesting of software interfaces within composite software services with an automated runtime platform. Other aspects can include innovative methods for routing the flow of invocation, inter-service communication, and exception handling. Industry standards are leveraged to integrate the methods to any computer system, programming language or software platform. The semantic-based and visual nature of the methods can significantly reduce the complexity of building, maintaining and deploying computer systems and software products.