An AWS SQS developer is responsible for setting up, managing, and optimizing AWS Simple Queue Service (SQS) - a fully managed message queuing service. They facilitate the decoupling and scaling of microservices, distributed systems, and serverless applications. Their duties involve creating new SQS queues, configuring queue parameters, managing message lifecycles, and monitoring queue performance. They ensure the reliability, durability, and scalability of the system. They also troubleshoot any issues related to SQS. The developer works closely with other team members to integrate SQS into the overall application architecture, ensuring efficient communication between different application components.