We trimmed the Sentry JavaScript SDK file size by 20% through a multi-faceted approach that involved improving release stability, conducting thorough testing, and implementing targeted optimizations such as reducing un-minifiable public class declarations, removing unnecessary TypeScript enums, and consolidating duplicate code. By achieving measurable success with minimal disruption to users, we now have a solid foundation in place to further optimize the SDK's performance, including tree-shaking support, async loading, and internal refactorings.