1. A distributed processing system comprising: a server digital data processor coupled to a rules base that stores a plurality of rules that define an application, wherein the server digital data processor operates on a cloud platform, an integration link used for communication of one or more data between the application and a tenant legacy system during execution of the application, wherein at least one integration rule among the plurality of rules defines the integration link, and wherein the tenant legacy system comprises at least one of a database and a web service that is communicatively coupled to the server digital data processor, one or more coordination modules associated with a respective one of the server digital data processor and the tenant legacy system that facilitate the communication between the tenant legacy system and the application in accordance with the integration rule and other tenant legacy system information accessible to the server digital data processor, and a firewall that is coupled to the one or more networks and that interrupts the integration link between the application and the tenant legacy system, absent intervention of the one or more coordination modules and the other tenant legacy system information accessible to the server digital data processor, wherein a tenant data center environment is simulated such that the one or more coordination modules and the tenant legacy system information accessible to the server digital data processor obviate a need to reconfigure the integration rule, so as to maintain the integration link regardless of execution of the application on the server digital data processor or a tenant digital data processor, and wherein the tenant legacy system is directly accessible to the tenant digital processor without the firewall preventing such access.