How we built a multi-tenant SaaS for clinic management

A multi-tenant platform means several clinics use the same system, but each one only sees its own data — patients, appointments and finance isolated between different clients.

The central technical challenge was isolating data per clinic without duplicating infrastructure for every new client. We solved it with NestJS + TypeORM on top of PostgreSQL, with tenant logic applied at the database layer, and AWS Lambda to scale processing without high fixed costs.

The system covers electronic health records with full appointment history, financial management with cash flow and goals, and SaaS subscriptions with different plans and limits per client — all integrated with Stripe for recurring billing.

This is the kind of project that only makes sense as a custom system: no off-the-shelf tool covers clinic management with this level of specificity (records + multi-tenancy + billing) at the same time.