Developed cross-backend arg_min and arg_max APIs for the narwhals-dev/narwhals repository, enabling direct retrieval of index positions for minimum and maximum values within Series and Expression objects. Focused on ensuring consistent behavior across Pandas, Polars, and PyArrow, the implementation unified analytics workflows and reduced the need for backend-specific code. Leveraged Python for API design, data analysis, and library development, with comprehensive testing to validate compatibility and correctness. The work emphasized API parity between Series and Expression, streamlining analytics pipelines and stabilizing core analytics paths, which lays the groundwork for future performance improvements and broader backend support.