A Modeler Developer is primarily responsible for designing and creating data models to meet business requirements. They use various modeling tools to represent complex data structures and their relationships. Their tasks include creating logical and physical data models, understanding business needs, translating them into database structures, and ensuring data integrity and security. They work closely with data architects and other IT team members to implement databases that efficiently store, retrieve, and manipulate data. They also often engage in performance tuning, data migration, and database troubleshooting to ensure optimal functionality of data systems.