38Ship a risky schema change to a 2 TB Postgres primary with near-zero downtime. How does that actually work?▼hard★ EssentialNewPhonePeStripeLinkedIn◆ premiumBlue-green works for stateless apps because instances are disposable. Databases are shared state, so safe migrations ride on backward compatibility and an explicit rollback boundary.Open full answer →
15You rolled back to the previous tag and errors continue. What is rollback actually made of?▼hardNewFlipkartPhonePeUber○ sign inRedeploying the old tag reverses code and nothing else. What separates staff-level answers is a per-change map of what rolls back in seconds, what rolls back in days, and what only moves forward.Open full answer →
