I've been waiting for ages for a Lisp that allows me to develop in one running system, creating minimized images with a tree shaker to distribute parts of the system for production when needed, and that never came (at least not with an affordable license, I don't know about the commercial Lisps). People recommend Smalltalk for this but that's not a Lisp. Eventually, I've switched to Go because if I have to write individual files in Emacs anyway, I can just as well use a more static language.