Zero-Downtime Database Migration at Scale

The platform needed two critical database migrations — an urgent MariaDB version upgrade followed by a full engine change to MySQL — on its primary production cluster. Traditional approaches required a maintenance window of up to 24 hours, costing $200K+ in lost bookings per window.

We engineered a blue-green migration methodology using bidirectional replication and progressive traffic cutover. Read traffic shifted first for validation, then writes migrated progressively with automated rollback triggers. The final cutover compressed to under 3 minutes.

Both migrations completed with under 3 minutes of downtime each. AWS launched its own native Blue/Green RDS Deployments feature 18 months later. Our approach became the internal standard and was documented in an AWS case study for a subsequent Aurora migration.