During December 2024, Lumi His worked on the epam/ketcher repository, focusing on resolving a Firefox-specific clipboard issue affecting static elements. By switching data serialization to the KET format for text/plain and stringifying objects, Lumi restored reliable Copy, Cut, and Paste functionality and improved log clarity. This targeted fix addressed a regression that disrupted core editing workflows, enhancing browser compatibility and user experience. The work demonstrated practical application of JavaScript and TypeScript in front end development, with an emphasis on deterministic data handling. Lumi’s contribution was precise and well-scoped, providing a robust solution to a nuanced browser compatibility problem.