A FluidUI developer is responsible for creating interactive and user-friendly interfaces using FluidUI, a high-fidelity prototyping tool. They design and implement mobile and web applications, ensuring optimal user experience by focusing on the look and feel of the application. They collaborate with UX/UI designers to translate designs into prototypes, test usability, and refine based on feedback. They troubleshoot and resolve issues related to the application's interface and functionality. Additionally, they may work with other developers and stakeholders, integrating their work into larger projects and contributing to the overall software development process.