An AWS AMI developer works with Amazon's cloud computing platform, specifically focusing on Amazon Machine Images (AMI). They create, manage, and maintain virtual servers using AMI, a scalable service that provides secure and resizable compute capacity. The AMI developer customizes instances to suit specific application or project needs, including configuring operating systems, applications, and network settings. They also ensure data security and system efficiency, troubleshoot issues, and optimize performance. Their role involves a blend of system administration, software development, and cloud management, requiring a solid understanding of AWS services and cloud computing concepts.