This is awesomely cursed: https://atgreen.github.io/repl-yell/posts/openldk-java-in-common-lisp/
"Java classes become CLOS classes. Lisp can add methods around methods written in Kotlin. A Clojure function can become something you pass to funcall. Java’s own compiler runs inside SBCL. And an initialized Spring Boot application can be saved in a Lisp image and launched again in about 84 milliseconds."