Hiring a data modelling developer is crucial for businesses dealing with large volumes of data. They help in structifying and organizing this data, ensuring it's easily accessible and interpretable. This aids in informed decision-making, predictive analysis, and strategic planning. Their skills can improve data management, reduce redundancy, and enhance data quality. They can also help in creating efficient database designs that ensure optimal system performance and data security. Overall, a data modelling developer can significantly contribute to leveraging your data to its full potential.