Welcome to your interview.
The question is on your right: Repartition vs Coalesce in Spark. 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 Spark, and when would you use one over the other?