Antonella Ritorto focused on improving simulation reliability in the OPM/opm-simulators repository by addressing a bug in serial-mode cell ID mapping. She corrected the timing of the syncDistributedGlobalCellIds call within CpGridVanguard.hpp, ensuring accurate parent-to-children mapping when toggling between global and distributed views. This targeted fix, implemented in C++ and grounded in software engineering best practices, enhanced the robustness and correctness of serial-mode simulations. By delivering a well-scoped, low-risk change, Antonella enabled more dependable simulation results and facilitated easier verification. Her work demonstrated a careful approach to simulation accuracy and contributed to improved test stability in the codebase.