A Cross-functional developer is a skilled professional who works across multiple functionalities in a project or organization. They are proficient in various programming languages, tools, and methodologies. Their duties involve designing, coding, testing, and improving systems or applications. They collaborate with different departments, such as design, testing, and operations, to ensure seamless product development. They also participate in problem-solving and decision-making processes. Their broad skill-set enables them to understand and contribute to different aspects of a project, enhancing team synergy and productivity. They are often involved in agile development processes, fostering innovation, and improving efficiency.