An Amazon CloudSearch developer is responsible for setting up, managing, and scaling a search solution for websites or applications. They configure and fine-tune search domains to ensure the delivery of relevant search results. They also manage text processing options like tokenization, stop words, and stemming to optimize search results. Additionally, they handle data uploads, monitor search traffic, and troubleshoot issues. They incorporate CloudSearch features like faceting and highlighting into applications to enhance user experience. They create and manage scaling and availability options to ensure high performance and reliability of the search solution.