We use GraalJS (part of GraalVM) and support upto ES2019 today. Here are some blogs and articles that might pique your interest: 1. https://www.oracle.com/a/ocom/docs/graalvm-netsuite-casestudy-new.pdf 2. https://www.netsuite.com/blog/suitescript-21-delivers-modern-javascript-syntax-for-server-side-development