First Interaction Credit

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 attribution team uses a first-touch model: every conversion is credited to the very first ad impression the user ever received, regardless of whether they clicked. A user counts as converted if they appear in the transactions table. For each converted user, return their user_id, the ad_campaign from their earliest impression, and that impression_time.

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