Building a SaaS product is not just about writing features. It is about making architectural decisions on day one that do not come back to haunt you when you hit 10,000 users. At Key Brains, we have been building SaaS platforms since 2009. We know where the bodies are buried — multi-tenancy traps, permission system explosions, billing edge cases at 2am — and we design around them before a single line of code is written.
What we build
Every SaaS engagement starts with a written architecture document. We define the data model, the tenant isolation strategy, the API contract, and the deployment topology before development begins. You approve it. Then we build it.
Our typical SaaS stack is React or Next.js on the frontend, Node.js or .NET on the backend, PostgreSQL as the primary database, and AWS or GCP for infrastructure. We provision everything with Terraform so your infrastructure is code from day one — not a collection of manually clicked checkboxes that nobody can reproduce.
Multi-tenancy done properly
We implement tenant isolation at the database level, not just the application level. Row-level security in PostgreSQL, separate schemas, or separate databases depending on your compliance requirements and scale targets. We make this decision with you based on your specific situation — not based on what was easiest to build.
Billing and subscription management
Stripe integration is a commodity. What is not a commodity is handling plan changes mid-cycle, prorated upgrades, failed payment retries, dunning sequences, and the inevitable “can we give this customer a custom price” conversation. We build billing systems that handle the real world, not just the happy path.
Authentication and access control
Role-based access control that actually reflects your product’s permission model — not a bolted-on afterthought. We implement RBAC with fine-grained permissions, team and organisation structures, SSO via SAML and OAuth, and audit logs that your enterprise customers will eventually require.
API-first architecture
Every feature we build has a corresponding API endpoint. Your web app, mobile app, and future integrations all consume the same API. No special-casing, no internal backdoors, no technical debt hiding behind server-rendered pages.
What you get
A production-ready SaaS platform with documentation, a CI/CD pipeline, monitoring, alerting, and a codebase your team can maintain and extend. Not a prototype dressed up as a product.