Build a SaaS with Next.js, Supabase and Stripe

Building a SaaS isn’t learning React. It’s wiring a dozen bricks — interface, database, authentication, payments, emails, deployment — into one product that holds when a real customer uses it. The hard part is never a single brick; it’s the assembly. Here’s the stack I use and the order I lay it down in.

The stack, and why it

Next.js (App Router) for front and back in one project. TypeScript to catch errors before the user does. Tailwind for fast, consistent UI. Supabase / Postgres for data and auth without rewriting a backend. Stripe for payments. Resend for transactional email. Vercel for deployment. Not the trendiest stack — the one that goes from prototype to production without swapping tools mid-way.

Order matters more than speed

The right sequence avoids rewrites. Start with the data model — tables, relations, constraints — because everything leans on it. Then auth and protected routes, then one core flow end to end, then and only then payments. Coding payments before you have a product that does something is the most common trap: you wire Stripe onto nothing.

Payments: where it breaks

Stripe Checkout handles the card form; your work is elsewhere. Never trust the price sent by the client — it’s decided server-side. The real core is the webhook: it confirms the purchase, unlocks access and sends the email. It must verify the signature and be idempotent, because Stripe resends the same event several times. A SaaS that grants access from the success page rather than the webhook always ends up handing out free access.

Emails and deployment

Transactional emails — confirmation, welcome, reset — go through Resend from a verified domain, with a clean fallback when the key is missing in dev. Deployment on Vercel is continuous: every push gets a preview, production promotes in one click. The invisible part — separate client/server env vars, secrets never exposed — is what separates a real product from a tutorial.

In one line

A modern SaaS is built with Next.js, Supabase and Stripe, in this order: data, auth, core flow, payments, emails, deployment. The stack is simple; the discipline of the assembly is everything. That’s exactly what Bynilson Build School teaches, from an empty repo to a product online.