A Data Mini Developer is primarily responsible for designing, developing, and implementing mini projects related to data management and processing. They work with various data types, including structured and unstructured data, to extract meaningful insights. They use programming languages like Python, Java, or SQL to manipulate, analyze, and visualize data. Their duties also include building algorithms and predictive models to solve complex business problems. They collaborate with data scientists and analysts to understand data needs and deliver effective solutions. They also ensure data quality and integrity, and maintain data privacy and security.