A FileNet developer is responsible for designing, developing, and implementing enterprise content management solutions using IBM's FileNet. They manage the complete life cycle of a project, including analysis, design, coding, testing, and maintenance. They also configure and customize FileNet workflows to automate business processes and integrate FileNet with other enterprise systems. They use APIs to enable the interaction of FileNet with other applications. Additionally, they are responsible for troubleshooting and resolving issues related to the FileNet environment. Regular communication with stakeholders to understand their requirements and provide technical support is also part of their role.