This is not an assumption, it&#x27;s an experience.  Code shipped to users.  In production.  In both Scala and Javascript bugs got through, both required specific practices to try to minimise them; with those practices, I found many bugs in the javascript code extremely quickly.  None of the bugs in the scala code were found quickly because the iteration cycle is poison (bear in mind, our code base was probably a worst case and may not be representative of scala in general).<p>I&#x27;m now firmly of the opinion that static vs dynamic typed is a sideshow, the real value is shifting as many errors as possible to as early as possible (in terms of seconds from typing the error to finding it) by whatever means you can, and a powerful type system is one tool for doing this, but if it compromises the iteration cycle and actually shifts the discovery of errors later in time then it&#x27;s undermined one of the major reasons for using it.