Worked on the vuejs/core repository to enhance the Vue.js Options API by enabling lifecycle hooks to return values, shifting the return type from void to any. This change was implemented using TypeScript and focused on improving the flexibility and type safety of plugin and external library integrations. By applying a targeted type fix, the update allowed developers to leverage richer interactions within the Options API while maintaining core performance and code maintainability. The work demonstrated a strong understanding of frontend development principles and contributed to more accurate typing, ultimately supporting a more robust and interoperable Vue.js ecosystem for advanced use cases.