Comment by FeepingCreature

LLMs massively reduce the cost of "let's just try this". I think trying to migrate your entire repo is usually a fool's errand. Figure out a way to break the load-bearing part of the problem out into a sub-project, solve it there, iterate as much as you like. Claude can give you a test gui in one or two minutes, as often as you like. When you have it reliably working there, make Claude write up a detailed spec and bring that back to the main project.