An Oracle APEX developer’s responsibilities are to design, implement, and maintain Oracle APEX applications. Oracle APEX, or Oracle Application Express, is a web application development tool for the Oracle database that allows developers to create attractive, responsive, and data-driven applications. As an Oracle APEX developer, your duties are to organize, protect, and maintain the security of the Oracle APEX platform. You’re responsible for programming and overseeing the application database, and you must follow system protocols and procedures. In this role, you also assist customers and clients with user applications.