I used to believe this, but what I discovered is that edit-time&#x2F;compile-time&#x2F;run-time phases are not as important as failing quickly in absolute time.<p>If I spot my error during compile-time in scala and only during run-time in javascript that is still a win for javascript if I found the error 1 second after writing it in javascript because that&#x27;s how long the page takes to load as opposed to 5 seconds in scala, because that&#x27;s how long sbt takes to compile.<p>Absolute time to discover the failure from writing it is important, not the phases that the error is discovered in, and despite this article, I still find that on complex project structures sbt&#x2F;scala is horribly slow.