A FontAwesome developer works with FontAwesome, a toolkit of vector icons and logos that can be customized in terms of size, color, drop shadow, and anything else that can be done with CSS. They integrate these icons into web or mobile applications for enhanced user interface and visual appeal. They also manage updates, ensure compatibility with various browsers or platforms, and may contribute to the development of new icons. Their role involves understanding client requirements, making appropriate icon selections, and implementing them effectively, ensuring that they enhance the user experience without affecting the application's performance.