This is purely anecdotal, and we could very well have done something wrong with our configuration, but I had my build iteration times cut in more than half afte

This is purely anecdotal, and we could very well have done something wrong with our configuration, but I had my build iteration times cut in more than half after switching our project to CommonJS + ES6 Typescript from es2015-preset Babel. I think we were using Gulp without any hot module replacement, so there are other ways we could have sped up our build time, but Typescript was good enough.