For larger tasks that I know are parallelizable, I just tell Claude to figure out which steps can be parallelized and then have it go nuts with sub-agents. I’ve had pretty good success with that.
This works great for refactors that touch a large number of files. You can knock out a refactor that might take 30 minutes, a persistent checklist, and possibly multiple conversations, and one-shot it in two minutes and a single prompt.