Testing enterprise software that communicates with a large number of other software systems is a challenging task as it is often difficult to replicate the size and heterogeneity of large enterprise environments. In particular, it is challenging to conduct testing of non-functional properties related to scalability, performance, and robustness of enterprise software systems when deployed into such environments. In order to address this issue, we propose the use of a scalable emulation environment enabling non-functional testing of enterprise software in realistic and large-scale settings. In this paper, we illustrate our approach by using deterministic finite state machines to specify a scalable and interactive emulation of a modeled environment. To demonstrate the practicality and scalability of the approach, a prototype tool is presented that is used to emulate a large-scale environment of up to 10,000 endpoint systems for an enterprise class software system.