Zero-downtime multi-cloud migration

The challenge

The platform had outgrown a single-region setup that was assembled in a hurry. Leadership wanted multi-cloud resilience and room to scale, but the product served customers around the clock and couldn’t afford a maintenance window.

Our approach

• Mapped every dependency and defined the target architecture as Infrastructure as Code.
• Built the new environment in parallel and replicated data continuously.
• Cut traffic over in phases behind feature flags, with a tested rollback at each step.
• Decommissioned the old stack only after the new one proved itself in production.