Experiment Impact

A hard SQL interview practice problem on DataDriven. Write and execute real sql code with instant grading.

Domain

SQL

Difficulty

hard

Seniority

L5

Problem

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.

Practice This Problem

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