I test my own code/scripts in dev when I’m working on it. QA usually tests acceptance criteria in test environment. And then staging is used for production data testing for performance and identifying missed edge cases. Actually, we sometimes use dev and test interchangeably when multiple people are working on the same repo, so the lines are a little blurrier than that.

As a data engineer, testing with production loads is critical to performance checking, as well as finding edge cases where your assumptions about what can be expected in the data are curb stomped and send you back to the drawing board to cry and think about what you’ve done.