Nils Vu worked on the IAS-Astrophysics/athenak repository, focusing on improving the reliability and efficiency of astrophysics simulation startup routines. He addressed a critical bug by correcting the Spectre BBH ID glob path, which resolved persistent data-loading errors and enhanced simulation setup accuracy. Using C++ and high-performance computing techniques, Nils introduced a timer to measure interpolation time during initial data loading, providing valuable performance insights for future optimizations. He also refactored the AMR refinement condition to use the correct pointer, increasing the stability of simulation initialization. His work demonstrated depth in debugging and optimizing complex scientific computing workflows.