Whoa I once got a 150kLOC code base in my possession and got it to 37kLOC in maybe two years.

I cut a lot of stupid boilerplate and was willing to cut features nobody needed. I added a lot of new, good features (not so good, too).

It was still not perfect, these days I would be much more fierce at shaking old stuff.

Still, you just delete and fix and delete and fix. That's how you make a turbo plasma rifle out of Singer sewing machine.