In this video from SC18, Mike Bernhardt from the Exascale Computing Project talked with Salman Habib of Argonne National Laboratory about cosmological computer modeling and simulation. Habib explained that the ExaSky project is focused on developing a caliber of simulation that will use the coming exascale systems at maximal power. Clearly, there will be different types of exascale machines,” he said, “and so they [DOE] want a simulation code that can use not just one type of computer, but multiple types, and with equal efficiency.”