The Modern SaaS Stack: Next.js 15 + Supabase + Stripe

Why This Stack?

Choosing a tech stack for your SaaS is one of the most consequential decisions you'll make. Here's why we chose Next.js 15, Supabase, and Stripe - and why we think it's the best foundation for building SaaS in 2025.

Next.js 15: The Frontend & Backend

Next.js 15 with the App Router gives you:

• Server Components - Fetch data on the server, send HTML to the client. Faster loads, better SEO.
• Server Actions - Mutations without API routes. Type-safe, validated, secure.
• Streaming - Progressive rendering for complex pages.
• Middleware - Auth checks, redirects, and i18n at the edge.

The App Router's async server components mean you can query your database directly in your page components - no useEffect, no loading states, no client-side data fetching.

Supabase: The Database & Auth

Supabase gives you Postgres with superpowers:

• Postgres - The most reliable relational database, hosted for you
• Auth - Email/password, OAuth providers, magic links
• Row Level Security - Fine-grained access control at the database level
• Type Generation - Generate TypeScript types from your schema

We use Supabase's service_role key server-side for maximum security, and the auth client for session management.

Stripe: The Payment Layer

Stripe handles the hard parts of payments:

• Checkout Sessions - Hosted payment pages that handle 3D Secure, taxes, and more
• Customer Portal - Let users manage their own subscriptions
• Webhooks - Real-time event processing for payment lifecycle events
• Global Payments - Support for 135+ currencies and dozens of payment methods

How They Work Together

User → Next.js (Server Component)
          → Supabase Auth (verify session)
          → Supabase Postgres (query data)
          → Stripe (payment status)
       → Rendered HTML sent to browser

User → Server Action (mutation)
          → Zod (validate input)
          → Supabase Postgres (update data)
          → Stripe (create checkout)
       → Redirect to Stripe Checkout

The entire flow is server-side. The browser never sees your database credentials, never makes direct API calls, and never handles sensitive data.

The Result

A fast, secure, production-ready SaaS that you can build on with confidence. That's what SecureStartKit gives you out of the box.