Which files could be removed for the production

I know that CI4 is a light framework out of the box, nevertheless I am looking for an idea which files could be removed in the production to make it even smaller. The installation is with -no-dev option, so test specific libraries are not included.  Any ideas?

You can remove many unused folders from /app/.

For example I only use those one:
- config, controllers, helpers, languages, libiaries, models, views + htaccess, common.php
Why those? Because I have my own libriaries, helpers etc.

I have removed "empty" folders:
- Database, Filters, ThirdParty