The role of a mobile app developer in a tech company involves designing, building, and maintaining applications for mobile devices. This developer is responsible for writing clean, efficient code, implementing user-friendly interfaces, and ensuring seamless performance across various platforms, such as iOS and Android. In addition to technical skills, mobile app developers collaborate with designers, product managers, and QA testers to create optimal user experiences. They must stay updated on the latest industry trends and technologies to deliver applications that meet user expectations and business goals.