Do you mean that it uses Spark even if I don't tell it to, somehow recognizing it? Because I am not using spark at all, I am using the exact same code as on local, and when I check spark jobs on the Databricks machine there is nothing (as I expect...).

I am using Databricks basically as a "local" machine that I can quickly deploy in the cloud, I am not intending to use any of the Spark / cluster functionality...