During August 2025, Kolja contributed to the ferdymercury/root repository by addressing a bug in the GDML output process related to CONST properties within the CreateOpticalSurfaceN function. Kolja enhanced the GDML writer’s handling of constant properties by iterating through and serializing all relevant CONST attributes, ensuring they were accurately exported in the GDML files. This targeted fix, implemented in C++ with a focus on geometry and GDML standards, improved the completeness and reliability of optical surface exports. The work demonstrated careful debugging and precise code changes, reducing the risk of missing data and streamlining downstream simulation consistency for users.