1. A computer-implemented method, comprising: integrating an enterprise service bus (ESB) with an existing application computing system at a connectivity level, the application computing system including one or more processing modules providing one or more functionalities, each of the one or more processing modules including a respective first proxy, the integrated ESB including one or more second proxies each associated with a respective processing module; in response to integrating the ESB with the existing application computing system, providing, by the integrated ESB, an access point to initiate an instance of the integrated ESB, the access point based on the connectivity level; determining that the connectivity level is an on-demand connectively level, and in response, providing an application programming interface to initiate the instance of the integrated ESB automatically and the information to employ the instance of the integrated ESB is returned and stored by the existing application computing system; determining that the connectivity level is an on-premise connectively level, and in response, providing a script to initiate the instance of the integrated ESB and the information to employ the instance of the integrated ESB is stored by the existing application computing system; receiving, by the instance of the integrated ESB, a message from a client computing device communicatively coupled with the application computing system, the message indicating a processing architecture associated with the client computing device; in response to receiving the message, providing, by the instance of the integrated ESB, instructions to the first proxy of a subset of the one or more processing modules through the one or more second proxies of the integrated ESB, wherein the subset of the one or more processing modules is selected based on the processing architecture associated with the client computing device and the instructions provided to the first proxy of the subset of the one or more processing modules are specific to the particular first proxy and based upon the functionalities associated with the processing module that includes the respective first proxy; in response to providing the instructions, managing, by the instance of the integrated ESB, the one or more processing modules of the application computing system such that the application computing system communicates with the client computing device; and transferring, by the instance of the integrated ESB, the one or more received messages between the application computing system to the client computing device by utilizing the subset of the one or more processing modules and the one or more functionalities of the application computing system.