This article was originally published on AI Study Room . For the full version with working code examples and related articles, visit the original post. Zero-Downtime Database Migration Strategies for Production Database migrations in production are terrifying — one mistake can corrupt data, cause downtime, or lock a critical table for hours. Yet every application needs them. This guide covers battle-tested strategies for running database migrations with zero downtime, including the expand-contract pattern, handling large tables, and reversible migrations. Migration Strategies Compared Strategy Downtime Complexity Best For Expand-Contract Zero High Schema changes on high-traffic tables Online Schema Change (gh-ost, pt-online-schema-change) Zero Medium ALTER TABLE on large MySQL tables Blue-Green Database Near-zero Very High Major version upgrades, risky operations Deploy + Migrate (simultaneous) Brief (seconds) Low Small apps with maintenance windows Shadow Table Migration Zero Medium Reshaping or cleaning…