Worked on the semgrep/semgrep-rules repository to enhance the CI workflow by implementing a custom changed-files detection mechanism. This solution replaced the external tj-actions/changed-files action with a Git-based approach, leveraging shell scripting and YAML configuration within GitHub Actions. By computing the merge-base with the develop branch and using git diff to enumerate changed files, the new workflow reduced external dependencies and improved determinism in pipeline execution. The changes provided finer control over when pipelines run, increased reliability, and improved maintainability of the CI process. All improvements were thoroughly documented to ensure traceability and ease of future maintenance.