This is a really good read, I'm surprised by how little the code needed to be adapted. Is it because they aren't using AoT compilation and therefore the classes can still be dynamically loaded?

Does that mean the JavaScript essentially gets compiled to a Jar?

How does graalvm bundles non jvm dependencies when your using the JIT compiler?

150% vs Nashorn is an important caveat here. At {employer} we started our SSRing via Nashorn and later moved to a separately deployed Node service for performance reasons... and saw a 4x drop in time per request for rendering tasks.