Context windows have grown significantly, the biggest one at are at 2 million tokens right now. That plenty enough, as even in his t codebase you don't need to

Context windows have grown significantly, the biggest one at are at 2 million tokens right now. That plenty enough, as even in his t codebase you don't need to feed the fill codebase in, you just need to provide the LLM a map of e.g. functions and where to find them, and the LLM can pull the relevant files itself as it plans the implementation path. And for that the current context window is plenty.