Tangential but I hadn't heard of Bun before and their performance claims had me interested, sadly seems you just can't beat V8 in the real world. I threw some poorly optimized art code I wrote yesterday at it and it's almost 2x as slow as when I run the same code in node.

Most of the speed ups seem to be in optimizations to the native code and porting js libraries to it. I'd expect pure javascript code to not have much of a difference. 2x sounds like you hit some limitations of JavaScriptCore itself.