Incremental compilation is pretty fast on Scala.js – it usually takes just a few seconds for me, about half of which is usually webpack bundling. Although if yo

Incremental compilation is pretty fast on Scala.js – it usually takes just a few seconds for me, about half of which is usually webpack bundling. Although if you make a code change that affects many modules of your app, it will take a bit more, but still very reasonable. I haven't had a chance to compare speeds apples-to-apples, but I expect Typescript incremental compilation to be faster than Scala.js. Though, to me this metric has stopped being relevant because using a type safe language I stopped looking at my changes in the browser every minute, like I used to do when I was writing frontends in Javascript. LESS/CSS compilation is the only part where I really care about speed since pixel pushing always needs trial and error, so I set it up to be separate from Scala.js compilation, and it's as fast as it would be in JS world.