A memcached developer specializes in utilizing memcached, a high-performance, distributed memory object caching system. Their main role involves using this open-source system to alleviate database load, enhancing the speed and performance of web applications. They are responsible for the integration of memcached into application code, optimizing data retrieval and storage processes. Additionally, they manage the caching strategies to ensure data consistency and integrity. They also troubleshoot any issues related to memcached, ensuring smooth and efficient operations. Their job requires deep understanding of distributed caching mechanisms, network protocols, and multithreaded programming.