Welcome to your interview.
The question is on your right: Repartition vs Coalesce and Caching. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
What is the difference between repartition and coalesce in PySpark, and when is it appropriate to use cache() or persist() for Plangrid ETL jobs?