A JetBrains WebStorm developer is a valuable addition to your team due to their proficiency in this powerful IDE. They can write, debug, and test high-quality code efficiently, thanks to WebStorm's intelligent coding assistance, navigation capabilities, and integrated tools for version control and issue tracking. Their knowledge of WebStorm's features, like live editing, auto code completion, and refactoring, enables faster development cycles. Furthermore, their familiarity with its in-built test runner and debugger for client-side code and Node.js ensures robust, error-free applications. They can also leverage WebStorm's support for modern frameworks to create cutting-edge web applications.