Worked on the DUNE/dunendggd repository to optimize ECAL geometry by aligning the active and passive slab thicknesses with detector specifications, directly improving simulation fidelity and detector performance. Used Python for configuration management and simulation tasks, ensuring that geometry changes were precisely implemented and thoroughly documented. Updated the project’s Markdown-based CHANGELOG to enhance traceability, providing clear records of all geometry modifications. Focused on detector physics principles to guide the adjustments, laying a stronger foundation for future geometry optimizations. The work emphasized maintainable documentation practices and careful configuration management, supporting more accurate and reliable detector simulations for ongoing and future development.