If you're building a SaaS product, your multi-tenancy architecture is the single most important technical decision you'll make. It affects your database design, security model, billing system, performance characteristics, and operational complexity. Choose wrong, and you're looking at a full rewrite.
The shared database with row-level security approach works for 80% of SaaS products. Every table includes a tenant_id column, and database policies ensure tenants can only access their own data. It's cost-effective, operationally simple, and scales well to thousands of tenants. We recommend this as the default starting point.
Database-per-tenant is necessary for regulated industries (healthcare, finance) where data isolation is a compliance requirement. Each tenant gets their own database instance. It's more expensive and operationally complex, but provides the strongest isolation guarantees. Use connection pooling (PgBouncer) to manage the connection overhead.
The hybrid approach gives you the best of both worlds: shared infrastructure for most tenants, dedicated databases for enterprise customers who require it. This is what we build most often — it lets you serve SMBs affordably while winning enterprise deals with isolation guarantees.
Stripe billing integration should be built into your architecture from day one. Implement subscription management with: trial periods, plan upgrades/downgrades with prorations, failed payment dunning, usage-based billing if applicable, and webhook handling for all payment events. Don't build billing manually — Stripe handles the edge cases you haven't thought of.
Tenant isolation testing is critical. Build automated tests that verify: Tenant A cannot access Tenant B's data via any API endpoint. Run these tests in CI/CD. One isolation bug can destroy customer trust instantly.
Plan for the real costs. At 10 tenants, any approach works. At 100 tenants, operational complexity starts mattering. At 1,000 tenants, your database connection management, migration strategy, and monitoring infrastructure become critical. Design for where you want to be in 18 months, not where you are today.
