Jim Gaffney is a physicist specializing in simulations of complex systems like materials under extreme conditions, high energy density physics and inertial confinement fusion. Much of his work is aimed at improving these models using experimental data, via Bayesian calibration and uncertainty quantification - often with novel deep learning methods and high performance computing resources in the mix. In the COVID era, Dr Gaffney has been adapting these methods to understand disease spread in small populations like Army units and schools; he has written several simulation software packages with this in mind.