Read the Plan
An easy Spark mock interview question on DataDriven, with an AI interviewer who asks follow-up questions and a hire or no-hire decision at the end.
- Domain
- Spark
- Difficulty
- easy
- Seniority
- L4
Interview Prompt
The platform team's order enrichment runs 12 minutes against a 4-minute SLA because the plan moves all of `retail_orders` across the cluster to join a 30 MB `stores` table. Work out why the planner passed on the cheaper strategy, then rebuild the enrichment so the orders side never moves, giving each order's id and amount with its store's name and region.
Summary
30 MB table. 80 GB shuffle. Read the plan.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write and run your Spark code against the tables
- Answer the interviewer's follow-up questions, then get a hire or no-hire decision