Maybe they need OO skills because the Clojure stuff will be interacting with OO stuff in other languages, and it'll be easier to communicate & collaborate with the other team if you have some familiarity with OO stuff?

Maybe they need OO experience so they can cherish their time with Clojure?

I hope the reason is that maybe it's a full stack job using cljs. ...But why have cljs on the FE and the other langs on the backend, I'll never know

CLOJURE ENGINEER Requires: - Some OO lang experience - Lots of OO - Definitely OO - Preferably in an OO language (or C) - HTML and JS, too ... - Oh yeah, and Clojure

someone who likes to hack in Clojure most likely also has hacked in OOP languages

although, really distilling the good parts of OO is orthogonal to Clojure. In my latest team I was the only one strongly pushing for defprotocol usage. Also I recall using Composite pattern (admittedly a easy/universal one, but you get the idea)

i've used defprotocol on my own software. for whatever reason, i prefer using elixir's version, but that's only after using it in clojure for awhile.

it was just for a boring use case.