A JDE Enterprise One developer designs, develops, and maintains applications in the JD Edwards EnterpriseOne ERP system. They use tools like JD Edwards Toolset, SQL, and other programming languages to create new modules, modify existing ones, and troubleshoot issues. They also handle system upgrades, patches, and security. They ensure data integrity and optimize system performance. They collaborate with stakeholders to understand their needs and translate them into functional requirements. They provide technical support, training to users, and document their work for future reference. They must stay updated with the latest technologies and industry trends.