Charles Denton focused on improving the performance reporting of the semgrep/semgrep CLI by addressing a bug in the slowest rules report. He modified the report to sort rules by actual runtime rather than alphabetically, ensuring that developers and security teams can accurately identify genuine performance bottlenecks. This targeted fix was implemented in Python, leveraging his skills in bug fixing and CLI development. Charles validated the change with existing tests to minimize risk and maintained compatibility with the --time flag, resulting in no regressions. His work demonstrated careful debugging, precise version control, and a clear understanding of performance analysis requirements.