I don’t know who is using mill but I’d guess Scala people and Scala frequently implies Spark which in turn implies PySpark. For instance I could see it being u

I don’t know who is using mill but I’d guess Scala people and Scala frequently implies Spark which in turn implies PySpark. For instance I could see it being useful for a team building a source connector which will be Scala-centric but need some PySpark additions as well. Even without Spark, Scala is frequently used for data centric applications and those kinds of teams would naturally be working with python as well.