Julia is a modern, dynamic, general-purpose, compiled programming language, particularly well suited for numerical computing. In this presentation I will talk about my experience with using Julia on very different HPC hardware, from the A64FX CPU on Fugaku (the then #1 supercomputer in the Top500 list) to the IPU, a massively parallel MIMD processor with interesting features for machine learning, showcasing applications ranging from solving differential equations to automatic differentiation.