Worked on the pandas-dev/pandas repository, focusing on core indexing logic within the pandas library. Addressed a critical bug in the length_of_indexer function, ensuring it returns non-negative lengths for negative-step slices with None bounds. This fix improved the reliability and correctness of slicing operations, particularly for reverse-interval indexing scenarios. The solution involved careful debugging, patch validation, and the creation of clear, testable code changes. Leveraged Python programming skills and deep understanding of data manipulation and analysis to resolve edge cases that could impact users. The work demonstrated attention to detail and a commitment to maintaining robust, predictable indexing behavior.