Practice Pinterest SQL Question | Real Coding Interviews | Hack2hire

NewML System Design & SQL tracks just landedSee what's new

Question Bank Pricing Blog Forum

Quick Summary

Calculate the percentage of users returning for a second purchase within seven days of their initial transaction.
Determine the earliest transaction date for each user to establish a baseline.
Compare all user transactions against this baseline to identify qualifying repeat purchases.

What This Tests

Aggregating data to find minimum values per group.
Joining summary results back to raw data for filtering.
Applying date arithmetic to define time windows.
Calculating percentages using distinct counts.
Handling edge cases like single-transaction users.

Common Patterns

Aggregation

Inner Join

Date Arithmetic

Deduplication

Test Cases

Input

-

Output

-

Expected

-