Multi-tenant SaaS Migration

A legacy SaaS needed to support multiple client environments while keeping data isolated and deployments safe.

• Isolate tenant data while keeping shared core services.
• Enable safe deployments without service interruption.
• Reduce onboarding time for new tenants.

The monolith mixed tenant data, had fragile deployments, and required a phased migration with no downtime.

• Legacy schema could not change abruptly.
• No downtime permitted for existing tenants.
• Multiple environments had to stay in sync.

We introduced tenant-aware data boundaries, staged migration tooling, and blue-green releases for safe cutovers.

• Tenant-aware data access layer with scoped queries.
• Migration pipeline with dual-write and validation.
• Blue-green deployments with automated rollback.

• Built tenant isolation middleware and data partitioning.
• Added migration scripts with verification checks.
• Automated deployment and monitoring workflows.

• Week 1: Audit, tenancy model, and migration plan.
• Weeks 2-4: Tenant isolation and dual-write system.
• Weeks 5-6: Cutover, monitoring, and stabilization.

• Reduced tenant onboarding time from days to hours.
• Achieved zero-downtime migration for active tenants.
• Improved deployment confidence with rollback tooling.