During December 2024, 15ug1 worked on the epam/ketcher repository, focusing on enhancing the quality and user experience of molecular editing tools. They addressed a critical bug in Snake Mode by refining the attachment point positioning for side chains, specifically updating the angle calculation to use a new rotation function when the attachment point is R1 and monomers are not horizontally aligned. This solution, implemented using TypeScript and leveraging front-end development skills, improved the accuracy of visual placement in the editor. The reusable rotation logic introduced not only resolved current issues but also laid groundwork for future geometry-based features in the codebase.