An H-Lookup developer utilizes the HLOOKUP function in spreadsheet programs, particularly Microsoft Excel, to find and retrieve data from a specific row across multiple columns. They create and implement formulas to search for specific values, typically in the top row of a table or array, to return a value in the same column from a row specified. These developers require advanced understanding of spreadsheet functionalities, data analysis, and problem-solving skills to create efficient solutions for data retrieval and management. They often work closely with data analysts, business analysts, and other stakeholders to develop and maintain data systems.