A LAMP stack developer is responsible for managing and developing applications in a LAMP environment - Linux, Apache, MySQL, and PHP. They create dynamic websites and web applications, ensuring efficient data storage and seamless functionality. Their tasks include writing server-side web application logic, developing back-end components, connecting applications with other web services, and supporting front-end developers. They also handle data storage solutions, optimize and validate code for improved efficiency, and troubleshoot to solve architectural challenges and performance problems. They must possess a deep understanding of the LAMP server stack and strong problem-solving skills.