Weighted Variant Selection

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

Domain

SQL

Difficulty

hard

Seniority

senior

Problem

The A/B testing platform uses rollout percentages to weight feature flag selection. Compute each flag's selection probability (its rollout divided by the total rollout across all flags) and its cumulative probability (the running sum of probabilities in rollout order).

Practice This Problem

Solve this SQL problem with real code execution. DataDriven runs your SQL queries against a live PostgreSQL database and grades it instantly.