Experiment Impact
A hard SQL mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- SQL
- Difficulty
- hard
- Seniority
- L5
Interview Prompt
Data science wants to rank A/B test performance inside each variant. For each (exp_name, variant) pair in experiments, compute the average outcome and participant count, skipping rows where outcome is NULL. Within each variant, rank experiments by average outcome from best to worst with ties sharing a position. Return the exp_name, variant, average outcome, participant count, and position.
Summary
Which experiments moved the needle? Rank them within each group.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write your sql solution with real code execution
- Get instant feedback and a hire/no-hire decision