A Magento developer works on creating and maintaining eCommerce websites using the Magento platform. Their responsibilities include designing and developing the architecture of the site, implementing front-end changes, integrating back-end systems, and ensuring the site's performance and functionality. They also manage customization of modules, troubleshoot integration issues, and optimize load speeds. They work closely with stakeholders and other developers to create a seamless user experience. They must stay updated on the latest eCommerce trends and technologies to ensure the site remains competitive. Additionally, they ensure high security and privacy standards for user data.