A system and method is disclosed for realistic performance testing of a computer network (e.g., a computer network of an electronic trading venue) based on a customizable test scenario, designed by users, executed using a plurality of independent computer nodes each connected to the computer network via its own physical connection to a network device (e.g., network switch) of the computer network. Using the system, developers may design a test scenario that includes testing parameters, which include computer executable code for transmission to and execution at the plurality of computer nodes. The computer executable code may simulate network traffic between devices of market participants and the electronic trading venue.