A Data Conversion Developer is responsible for designing, implementing, and managing the process of transferring data from one format or system to another. They work with various databases and systems to ensure seamless data migration, maintaining data integrity and security throughout. Key tasks include understanding source data systems, defining data mapping, developing scripts or tools for data extraction, transforming and loading (ETL), and resolving data quality issues. They also perform testing to verify successful data conversion and collaborate with different teams to understand and fulfill their data requirements. Their role is crucial in system upgrades, integration, or consolidation projects.