[rekabis]

I disagree. Testing with multiple rounds of feedback and iteration, with merging and related work done, with everything in production and available to the users is done, but is it perfect?

Not necessarily.

I see it as having dealt with all low-hanging fruit. Of handling anything reasonably expected at that point. Bugs will remain. Exploits will doubtless be found. But so long as all reasonable efforts were made to find and deal with them, that is good enough.

Because a perfect product will never be done.

And a done product cannot possibly ever be perfect.