From single-tenant to 3× faster multi-tenant SaaS

A UK B2B software company had a product customers liked and an architecture that was holding it back. Each new client got its own isolated deployment — its own database, its own infrastructure, its own release to babysit.

The problem

Single-tenant isolation felt safe and cost the company its momentum. Onboarding a customer took weeks of provisioning. Shipping a feature meant rolling it out across every deployment. Infrastructure spend rose with every logo, and the engineering team spent more time operating copies of the product than improving it.

What we built

We rebuilt the platform as a true multi-tenant system: one codebase, one deployment, strict data isolation enforced at the database with row-level security rather than by running separate servers. We added a self-serve onboarding flow so a new customer is live the same day, and a tenant-aware billing and admin layer so the team manages accounts from one place.

The migration ran tenant by tenant behind feature flags, so existing customers moved across without a disruptive cutover.

The result

The product scales with customers instead of straining against them.

• Page loads roughly 3× faster after the rebuild
• Infrastructure cost per customer down 34%
• Onboarding went from weeks to under a day, self-serve

Engineering is back to building the product, not operating dozens of copies of it.

Figures are anonymized at the client's request.