I am a theoretical astrophysicist using computer simulations to understand the physics of the plasma near extreme objects such as neutron stars and black holes. My main tool is a "Particle-in-Cell" code Aperture that I developed as a part of my PhD thesis. It simulates ultra-relativistic plasmas in strong electromagnetic fields, and their interaction with high-energy radiation. The code runs on GPUs, is highly optimized, and enables me to run simulations on my personal workstation that would otherwise take thousands of CPU cores. It also runs on the Summit supercomputer at the Oak Ridge National Labs, parallelized over tens of thousands of GPUs. I also work on interactive visualizations of astrophysical simulations in the modern browser. Feel free to check out my GitHub: https://github.com/fizban007.