Know what a folder contains
Build output and downloaded dependencies can grow across old projects. Names such as node_modules, build and virtual environments are clues, not permission to delete every matching folder.
Keep source files, dependency manifests, lockfiles, credentials and local databases. A virtual environment can also contain changes or data that were never saved elsewhere.
Check how you would rebuild
Close the relevant tools and finish active builds before cleaning. Confirm that the project has the files and tool versions needed to reinstall dependencies or rebuild output. A fresh install may need network access and time.
In CleanPanda, review the project path and the explanation for a developer finding. Choose projects you recognise. Skip anything whose ownership or purpose is unclear.
Test before emptying the Trash
Remove a small selection first, then reopen the project and run its normal build or tests. Some caches will grow again as tools use them; that is expected.
Keep the removed items in the Trash until the project works. Use Activity to undo if something needed was included. Do not empty the Trash during the check.