Idiomatic Clojure is slower than JS, but you can make Clojure somewhat close to Java by writing Java with parenthesis(lots of interop from Clojure). One of the

Idiomatic Clojure is slower than JS, but you can make Clojure somewhat close to Java by writing Java with parenthesis(lots of interop from Clojure). One of the devs of Datomic brag about how it was only 200KLOC of Clojure, but if you extract the datomic tar, the lib dir has probably more that 2Million LOC of open source Java libs.