The advent of powerful cosmological surveys demands a new generation of high-precision, large-volume, and high dynamic range simulations of structure formation in the Universe. Key aims of these simulations are understanding why the expansion of the Universe is accelerating and what dark matter is made of. The availability of Roadrunner, the world's first petaflop platform, led us to develop a new hybrid cosmology simulation code making essential use of hardware acceleration. We describe the strategies underlying the code and aspects of its implementation.