Glossary
Smart Clean
Disk Housekeeper's cleaner for developer caches and node_modules, behind a preview.
Smart Clean is the feature that gathers the heavy, recreatable developer files: caches such as npm, Gradle, and Cargo, Xcode DerivedData, and node_modules. It is not a scan that deletes System Data as a blob, and it is not a snapshot tool.
Like every clean in Disk Housekeeper, it previews first and sends removals to the Trash by default. Choose the items you recognize. The guide How to clean developer files on macOS links the per-cache pages.