Man that seems like an awful lot of ceremony for a trivial web app. Surely the language known for macros and building your own DSLs has a more concise way to get a web app up and running?
[0]: It came out shorter than the guestbook demo in Python-Flask.
https://www.youtube.com/watch?v=A4PzSsOD-CQ
(also, the top comment is gold)
(defparameter *web* (make-instance '<app>))
@route GET "/"
(defun index ()
(render #P"index.tmpl"))
https://github.com/fukamachi/caveman/ (I like Mito and Djula, I'd go with Hunchentoot rather than Clack which is famously undocumented)