A heuristic usability evaluation developer conducts assessments of user interfaces based on established usability principles, known as heuristics. They scrutinize interfaces, often in the development phase, to identify potential issues that could hinder user experience. They focus on essential aspects such as simplicity, consistency, feedback, error tolerance, and flexibility. They guide the design process to ensure it is user-centered, improving efficiency, effectiveness, and satisfaction. They also document identified usability problems, suggest improvements, and often collaborate with designers and developers to implement the changes, thereby enhancing overall product usability and user satisfaction.