Next.js SaaS Architecture: What Actually Matters Early

"What's the best architecture for a SaaS?"

Wrong question. The right question is: "What architecture decisions actually matter right now?"

Most founders over-engineer. They build for scale they don't have, optimize for problems they'll never face, and delay launch for architectural purity.

Here's what actually matters when you're building a production-ready SaaS with Next.js.

Decisions That Matter Early

1. Authentication Strategy

Get this wrong and you'll rewrite it later. Get it right and you'll never think about it again.

• Use a managed solution — Supabase Auth, Clerk, or Auth.js
• Support magic links — lowest friction for users
• Add OAuth — Google at minimum
• Store sessions properly — httpOnly cookies, not localStorage

2. Database Schema

Your data model is your product. Think about it.

• Users and profiles — separate concerns
• Subscriptions tied to users — not accounts
• Leads as first-class entities — not just email addresses
• Audit timestamps — created_at, updated_at on everything

3. Payment Integration

Stripe is the obvious choice. The architecture around it matters more.

• Webhook handlers — for every event that matters
• Customer portal — let users manage their own billing
• Subscription status synced — to your database, not just Stripe

Decisions That Don't Matter (Yet)

• Microservices — you don't need them until you have a team
• Kubernetes — Vercel/Railway handles this for you
• GraphQL — REST is fine. tRPC is great. GraphQL is overkill.
• Event sourcing — cool, but you're not a bank
• Multi-region — your users are probably in one country

Every hour spent on premature optimization is an hour not spent on your product.

The Practical Stack

For a Next.js SaaS starter, this stack covers 99% of use cases:

• Next.js 14+ — App Router for modern patterns
• Supabase — Auth + Postgres in one
• Stripe — payments and billing
• Tailwind + DaisyUI — styling without bikeshedding
• Vercel — deploy and forget
• Resend — transactional emails

This isn't cutting edge. It's proven. And proven ships faster.

Architecture Is a Means, Not an End

The best architecture is the one that gets you to paying customers fastest. Everything else is premature optimization.

LaunchKit uses this exact stack. Production-ready SaaS architecture, already built.

Get LaunchKit →