Henry Huck enhanced error handling in the getsentry/sentry-javascript repository by developing an explicit 'handled' prop for the React SDK’s ErrorBoundary component. This feature allowed developers to mark errors as handled directly, replacing the previous implicit behavior tied to the 'fallback' prop. By introducing this explicit error categorization, Henry improved both the reliability and observability of error handling in frontend applications. The work was implemented using JavaScript and TypeScript, leveraging skills in React and error handling. The change provided clearer developer control, reduced silent failures, and supported more efficient code review and traceability through a well-documented feature commit.