1. A method comprising: at a platform system: the platform system assigning a primary application resource identifier and at least a first status application resource identifier to a first application, wherein the primary application resource identifier is a resource identifier of a first application server system that is external to the platform system, and wherein the first status application resource identifier is a resource identifier of one of the first application server system and a second application server system that is external to the platform system; responsive to the platform system initiating a session of the first application at the platform system, the platform system communicating with the first application server system by using an application layer protocol, wherein communicating with the application server comprises: embedding at least a portion of state information of the session of the first application in a first application layer protocol request, sending the first application layer protocol request through the application layer protocol to an application resource identified by the primary application resource identifier, and receiving a first application server response from the first application server system, the platform system processing the first application server response; and responsive to an application status change event of the session of the first application, the platform system: embedding at least a portion of state information of the session of the first application and the application status change event in a second application layer protocol request, and sending the second application layer protocol request through the application layer protocol to an application resource identified by the first status application resource identifier.