Contributed to the pandas-stubs repository by implementing support for the calamine engine in the ExcelFile class, enhancing cross-engine compatibility for Excel file handling in Python. The work involved updating type hints to include the new 'calamine' engine, ensuring accurate type checking and improved validation for downstream users. Comprehensive tests were added to verify that Excel files could be read correctly using the calamine engine, increasing the reliability of type hint coverage. The technical approach focused on Excel handling, type hinting, and testing, resulting in a targeted feature that improves both developer experience and code quality within the pandas-stubs project.