Worked on the epam/ketcher repository to enhance the quality and user experience of molecular editing tools, focusing on a critical bug fix in Snake Mode. Addressed an issue with side-chain attachment point positioning by updating the angle calculation logic to use a new rotation function when the attachment point is R1 and monomers are not horizontally aligned. This solution, implemented using TypeScript and front-end development skills, corrected the visual placement of side chains, improving editing accuracy and reliability. The reusable rotation logic introduced in this fix also supports future geometry-based features, contributing to more maintainable and extensible code.