With every novel I've ever written, there comes at least one revision (usually after the first round of CP feedback but sometimes earlier) when I have to completely overhaul my manuscript. Usually gutting 40, 50, or even 80 percent of my novel to rework some major character or plot development.
With A STOLEN THRONE, I cut a major character, added a bunch more, and scrapped an entire subplot I expected to use in book 2 (guess not!). I redid basically everything from the 25% mark all the way to the end.
During the course of revisions for THE TRIAL, I had one major revision where I had to do adjust the entire voice for one of my POVs, add characters and depth, and strengthen the romantic plot. While there wasn't a lot of cutting involved (at least not to the extent with AST), I did have to create a whole lot of new content.
And with my latest project, BURNING SALEM? I had to completely redo everything after Chapter One.