Your small dive prompted me to create a simple version of what you were describing [1]. I didn't use my usual editor, and just used the cljsfiddle itself.

I really wanted to create a spec for the data in app-state, and check the value in the app-state atom each time I edited it (perhaps with an add-watch). That gets you many of the same advantages of static typing, but you only add the extra insurance when you think its worthwhile instead of always.

Instead of using strings for time-choices and page-choices (in the code at [1]), you can use maps like

    [{:title "Day" :time 24}, {:title "Hour" :time 1}...]

and expand when nessicary. It shouldn't be too difficult to keep them in sync this way.

You might want to check out clojurescript again sometime soon. Clojure.spec (and cljs.spec) are going to offer a huge jump in usability. Clojure.spec is a tool kit, and specs are basically definitions of data, that can be used for parsing, unparsing, and generating that very data. The beginning of this (interactive, cljs driven) blog post shows clojure.spec off a bit.

[1] - http://escherize.com/cljsfiddle/#gist=eea10854f99ef124f8dc15...

[2] - http://blog.klipse.tech/clojure/2016/10/10/defn-args.html