What you get
The causes, not the symptoms — and the paths that stay open
The product's real state, why it got there, and the paths that stay open: discard and rebuild, keep the old alongside the new while serving users with a mix, or recover it piece by piece. Each comes with its own timeline, its own cost, and what it takes while the product keeps running.
The fastest path is not always the one worth taking. Which one it is depends on things we know about the code and things you know about the product: that's where the choice gets made, together, with the numbers on the table.