A message queuing developer designs, deploys, and maintains systems that facilitate asynchronous data transfer between different parts of an application, or between different applications. They work with message queuing technologies like RabbitMQ, Apache Kafka, or Amazon SQS, which allow for decoupled, reliable, and scalable communications. They handle tasks like setting up message brokers, designing messaging protocols, ensuring message delivery, and handling potential issues like network failures or slow consumers. They also monitor system performance and troubleshoot any issues, ensuring efficient data flow and minimal downtime. This role is crucial in distributed systems and microservices architectures.