GCP - Find which projects are being used and which projects are empty and not used

Question

I have old Google cloud platform projects that we aren't sure for 100% that are not being used.

We have checked the API usage, and activity, but is it enough? What checks do you do to verify you can delete it?

Answer 1

API usages and logs are the good places.

In addition, you can also check the most important resources and backup them to be sure that no one use them.

Eventually, and in the worst case, you can undelete a project within the 30 days after the deletion, if you missed something wand want to rollback the deletion.