If you want another example, checkout coffeemug's cl-cont [1], with the full source here[2]. It's no accident some of the best software like RethinkDB have people behind them that are deeply rooted in the mind-blowing.

[1] - http://common-lisp.net/projects/cl-cont/

[2] - https://github.com/skypher/clbuild.mystic/tree/master/source...