Methods and systems for specifying the state of an application interface during configuration of the business system are provided. A state controller can manage communication between application interfaces and interface proxies. Each interface proxy replicates the services exposed by an application interface associated with backend applications in a business system. The state controller allows each application to operate in a stateful mode, a stateless mode, or a combined mode. The mode for an application can be specified during configuration/installation of the business system, removing the need to specify communication modes for applications during design and development of the applications and business system. The use of an interface proxy allows user interface (frontend) application to be developed and/or configured individually, and without regard to the communication mode used by the backend applications.