Infant Mortality

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

Domain

SQL

Difficulty

hard

Seniority

L4

Problem

We run periodic health checks on every service and want to catch the ones that were troubled from birth. Among services whose earliest check falls in Q1 2026, surface those where more than 20% of all their checks came back as something other than healthy, along with that failure rate.

Summary

The youngest ones break first.

Practice This Problem

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