Today, ES2017 is the closest to modern syntax and tools such as npm, Babel, webpack, and Rollup have made it possible to configure your build system and write your packages using this syntax. This post covers several approaches, and you should use the easiest option that works for your use case.

"webpack is a fantastic, versatile, tool that does not need to cost the earth. These techniques have helped us reduce our median build time from 170 to 17 seconds and, while they have done much to improve the deployment experience for our engineers, they are by no means a complete work."