Smooth Latency

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

Domain

SQL

Difficulty

medium

Seniority

L5

Problem

Some of our API endpoints look like they are drifting slower as traffic grows, and we want the underlying trend rather than the per-call noise. For each endpoint, walk its calls from oldest to newest (breaking ties by call_id) and, at each call, report the average latency across that call and every earlier one, skipping any call with no recorded latency.

Summary

Noisy latency readings, smoothed into a trend you can trust.

Practice This Problem

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