If you go back and forth with chatgpt/gemini on architectural details first, then get chatgpt to produce a hyper detailed spec (like, almost a program claude can execute), you can get claude to run for 2-3 hours at a shot (particularly with a hook to prevent early stopping). Require >85% test coverage, and bake very clear e2e test paths into the spec, and Claude can come surprisingly close to one shotting big things.