Code Room
Vibe codingHardvc-g595
Subject Ai verificationLevel Senior–Staff~22 minCommon in Algorithms & data structures interviewsIndustries Software development, Technology

Question

An agent generated a Postgres migration to backfill a new `normalized_email` column across a 200-million-row users table and ran fine against your local 5,000-row dev database. You don't fully understand its locking behavior or the backfill batching. It's queued for production. How do you verify it's safe to run against the real table without taking the site down?

What a strong answer looks like

Treat the AI’s output as a draft to verify, not an answer to trust. Name the specific flaw and the input that triggers it, say how you’d catch it — tests, edge cases, reading critically — and how you’d re-prompt or decompose to get it right.

Describe your solution

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.