[vorg]

> our defect rate in production dropping by 90% (!!!) when we switched from Groovy to Scala, with a notable increase in productivity)

> Occasionally I want to whip up a quick script, so will just hack it together in Python

Languages like Python and Groovy were originally created to be scripting languages for quickies. Of course what starts off as a short script can easily evolve into a larger production system. Groovy's creator James Strachan based Groovy closely on Java syntax specifically to provide a seamless upgrade path from Groovy to Java when such scripts grow into something larger. He even put in runtime type tags which would become compile-time types without any syntactic changes when code was converted from Groovy to Java. Groovy was innovative beyond its peers Python and Ruby in that way, intended to be a dual dynamic language to statically-compiled Java, enabling easy conversion to the main language when required. Other languages like C# and Scala solved that issue with type inference and by adding a "dynamic" type into the main language instead.

Unfortunately after Strachan was replaced, the management policy regarding Groovy's purpose changed. All work on a spec to encourage alternative implementations was dropped, and a user-contributed plugin enabling static compilation was duplicated into the main Groovy distribution for version 2. Groovy was then pitched as an alternative to Java, competing head on. They don't mention in their marketing, however, that a mere one person wrote Groovy's static code compared to the hundreds who contributed to Java's, and or even to Scala's. Therefore adopting Groovy for static compilation is very risky, a possible cause for your huge defect rates in production.