Develop new user-facing features. Build reusable code and libraries for future use. Ensure the technical feasibility of UI/UX designs. Optimize application for maximum speed and scalability. Design mobile-based features. Collaborate with back-end developers and web designers to improve product usability. Get feedback from, and build solutions for, users and customers. Write functional requirement documents and guides. Help back-end developers with coding and troubleshooting. Assure that all user input is validated before submitting to the back-end. Collaborate with other team members and stakeholders. Stay up-to-date on emerging technologies. Assist in building up, training and mentoring other junior/entry frontend developers of the company.