Andrew Peace refactored the benchmark scripts for the awslabs/mountpoint-s3 repository, focusing on improving maintainability and reproducibility in performance testing. He introduced a configurable debug mode using environment variables, allowing developers to toggle detailed output as needed. By consolidating the read and write benchmark logic, Andrew reduced code duplication and streamlined the execution flow while preserving the core benchmarking functionality. His work, implemented using shell scripting and benchmarking techniques, maintained compatibility with existing benchmarks and CI pipelines. The refactor addressed the need for safer experimentation and more deterministic results, enhancing the reliability of performance tests without introducing new bugs.