In Oct 2024, delivered robust data cleaning improvements for the ONSdigital/monthly-business-survey-results repository, enhancing data integrity and reliability of the data processing pipeline. Refactored data cleaning logic to optimize lambda usage in run_live_or_frozen and implemented conditional replacements in correct_values, resulting in more accurate handling of the frozen column and NaN edge cases. Updated tests to reflect the new behavior, ensuring future changes remain aligned with production expectations. Also resolved pre-commit hook issues to stabilize CI and reduce development friction. These changes improve data quality for monthly business survey results, reduce manual validation effort, and strengthen CI reliability.