Worked on the pola-rs/polars repository to improve the correctness and reliability of horizontal concatenation (HConcat) in data processing workflows. Addressed a bug where negative-offset slices could cause misalignment when concatenating inputs of unequal lengths, ensuring that such cases are now handled properly. The solution involved targeted changes in Rust, complemented by comprehensive regression tests to validate the fix and prevent future regressions. Collaborated closely with team members to maintain high code quality and thorough documentation. Leveraged skills in Rust and Python programming, data processing, and unit testing to enhance the maintainability and data integrity of the HConcat functionality.