A cardsorting developer is responsible for organizing and structifying information in a user-centric manner to enhance user experience. They conduct card sorting exercises, where users categorize and prioritize different pieces of information into groups, helping developers understand user logic and expectations. This reveals patterns, preferences, and expectations of the users, which guides the design of intuitive and efficient navigation and information architecture in software, websites, or apps. They may use open, closed, or hybrid card sorting methods and use tools like OptimalSort, Trello, or UsabilityTools for the process. Their goal is to improve usability and overall user satisfaction.