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

The data science team is auditing how each experiment fared inside the variant buckets it ran in: for every experiment and variant pairing in experiments, take the average outcome and the participant count, ignoring rows where the outcome was never recorded. Within each variant, ordered from the highest average outcome down, give each experiment a competition standing where tied experiments share a slot and a slot equals one plus the number of experiments in that variant with a strictly higher average, plus a tier standing where ties again share a number but the numbers stay consecutive with no gaps so the next lower average is always the next number up. Return the exp_name, variant, average outcome, participant count, competition standing, and tier standing.

Summary

Which experiments moved the needle? Settle the standings inside every variant.

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