1.Convert web designs to HTML
2.Style new websites and maintain existing websites
3.Client side programming/scripting
4.Develop new user-interface features
5.Build reusable code and libraries for future use
6.Optimize application for maximum speed and scalability
7.Ensure that all user inputs are validated before being submitted to back-end
8.Collaborate with other team members (backend developers, product owners, customers and other stakeholders) to get the final quality website ready.