A Data Mapping Developer is responsible for designing, implementing, and managing the process of data transformation between different systems. They create data maps that detail how data from one system fits into another, ensuring the accurate transfer and integration of data. Their tasks include identifying the data needs of different systems, developing algorithms for data conversion, and testing the mapping to ensure data integrity. They also troubleshoot mapping errors and improve data quality. They work closely with data analysts, data scientists, and other stakeholders to ensure seamless data flow across various systems.