Open Robotics has a rich history of creating robotics competitions where open source software and simulation are core to the competitions’ foundation and success. One of the newest competitions is the DARPA Subterranean Challenge. The SubT is pushing the limits of what has been done before — how to rapidly map and navigate some of the most complex underground environments — using multiple robots over expansive distances. Ian Chen, Research Engineer at Open Robotics, will share some of the challenges and lessons learned from building and hosting large scale cloud-based competitions, how simulation has benefited robotics development and virtual competitions, and the impact of these competitions on a variety of industries.