Tenti refined the SAND ECAL endcap geometry within the DUNE/dunendggd repository, focusing on accurate simulation for detector studies. They implemented detailed C-shaped volumes and integrated both active and passive layers, ensuring the geometry closely matches physical specifications. Using C++ and Geant4, Tenti refactored endcap components and developed logic for precise module placement and material definition, supporting downstream analysis and calibration. The work addressed issue #40 and enhanced the fidelity of ECAL-related physics simulations. Tenti’s approach demonstrated depth in detector geometry modeling and object-oriented programming, resulting in a robust, maintainable codebase for future development and analysis needs.