Yes. Most of the simple stages just invoke the Spark Scala API - for example MLTransform invokes a pretrained SparkML model against a dataframe and returns a new one. You can see the standard Spark ML call: https://github.com/tripl-ai/arc/blob/master/src/main/scala/a.... You can add any plugin you want via the interface: https://arc.tripl.ai/plugins/

This is really defining a dialect that is more simple for Technical Business Analysts to consume that is safer than code and a notebook environment to interactively build with.