A JiBX developer works with the JiBX framework, a tool for binding XML data to Java objects. They define how Java objects relate to XML structures, enabling conversion between the two. This involves writing binding definitions, debugging, and optimizing performance. They use JiBX to transform data from XML to Java and vice versa, enabling applications to communicate and exchange data. They may also work on web service development, as JiBX can be used in SOAP-based web services for data representation. The developer needs to have strong knowledge in Java, XML, and ideally, experience with other binding frameworks.