I'm more into Scheme than CL, but am aware of Coalton. My current lisp is Gerbil: https://cons.io https://cons.io which already has a type annotation system and

I'm more into Scheme than CL, but am aware of Coalton. My current lisp is Gerbil: https://cons.io https://cons.io which already has a type annotation system and will be enhancing it for the next major release (v19).