Are the devs behind the models adding their own state somehow? Do they have code that figures out a plan and use the LLM on pieces of it and stitch them togethe

Are the devs behind the models adding their own state somehow? Do they have code that figures out a plan and use the LLM on pieces of it and stitch them together? If they do, then there is a plan, it's just not output from a magical black box. Unless they are using a neural net to figure out what the plan should be first, I guess. I know nothing about how things work at that level, so these might not even be reasonable questions.