How to Build a SaaS MVP
From Zero to Live in Days
Building a SaaS MVP is the highest-leverage thing a founder can do in the early stage. It transforms an idea into evidence. This guide covers everything you need to know — architecture decisions, feature scoping, authentication, billing, and deployment — so you can go from a blank repository to a live, paying-ready product in days rather than months.
Talk to an ExpertWhat is a SaaS MVP and why it is different
A SaaS MVP is a web-based product that delivers a specific, recurring value to a specific user — and charges them for it, or is designed to charge them for it soon. It is different from a regular MVP because it introduces recurring revenue mechanics (subscriptions, usage-based billing, or seat-based pricing), multi-tenancy concerns (each customer's data must be isolated), and authentication complexity (email/password, OAuth, magic links, or SSO). A SaaS MVP is not a simple landing page or a one-time purchase flow. It is a product that users log into, get ongoing value from, and would miss if it disappeared. That distinction shapes every architectural and scoping decision you will make. The earliest stage of a SaaS MVP should prove one thing: will someone pay a recurring fee to solve this problem using this product? Everything else is secondary until you have that answer.
Delivers recurring, ongoing value — not a one-time transaction
Requires multi-tenancy: each user's data is isolated
Authentication is a core requirement from day one
Billing infrastructure must be in place before or at launch
Success metric: will someone pay monthly for this?
Scope to one core workflow before adding secondary features
How to scope your SaaS MVP ruthlessly
Scope is where most SaaS MVPs die before they are even built. Founders have a vision of a complete product — with dashboards, integrations, team collaboration, mobile apps, and a help centre — and try to build all of it before launch. The result is a product that takes six months to build, costs a hundred thousand dollars, and launches to a market that has moved on. Scoping an MVP means identifying the single workflow your product must nail to prove that users will pay for it. Not two workflows. Not one workflow plus 'nice to have' features. One workflow, done perfectly. Start by writing a one-sentence description of the problem your user faces and the one action your product takes to solve it. Every feature you consider should be tested against this sentence: does it serve that one action? If not, it does not belong in the MVP.
Identify the single core workflow that proves willingness to pay
Write a one-sentence problem statement and test all features against it
Cut anything that does not serve the core workflow — add it post-launch
Time-box the MVP: what can be built in two weeks?
Define your launch criteria before you start building
Talk to 10 potential users before writing a single line of code
Choosing the right tech stack for a SaaS MVP
The best tech stack for a SaaS MVP is the one your team knows best and that has the largest ecosystem of libraries, tools, and documentation. This is not the time to experiment with new technologies. At Greta, we default to Next.js for the frontend and full-stack API routes, Supabase or Postgres for the database, Stripe for billing, and Vercel for deployment. This stack has been battle-tested across hundreds of SaaS products, has excellent documentation, and allows a small team to ship a full-stack product in days. The key principle is to use managed services for every piece of infrastructure that is not your core product. Your database, email delivery, authentication, and billing should all be handled by proven third-party services. The only code you should write is the code that makes your product unique.
Use the stack your team knows — no tech experiments at MVP stage
Next.js + Supabase + Stripe + Vercel: a proven SaaS default stack
Use managed services for auth, email, billing, and storage
Write only the code that makes your product unique
Choose tools with large ecosystems and strong documentation
Plan for scale from day one — use multi-tenant data patterns
The core features every SaaS MVP needs
Every SaaS MVP — regardless of its specific domain — needs the same foundational set of features. Authentication allows users to sign up, log in, and manage their account. A dashboard gives users a home screen that reflects their data and status. The core feature is the one workflow that solves the problem you identified. A settings screen allows users to update their profile and preferences. An onboarding flow guides new users to their first value moment. And an empty state — what users see before they have created any data — is often the most important UX screen you will build. These features are not glamorous, but they are the table stakes for any SaaS product. They must be solid before you build anything else.
Authentication: sign up, login, password reset, OAuth
Dashboard: a personalised home screen with the user's data
Core feature: the single workflow that solves the problem
Settings: profile, account, notification preferences
Onboarding: guide users to first value in under five minutes
Empty states: the UX that converts new users into active users
Billing and authentication — getting it right
Billing and authentication are the two most critical pieces of a SaaS MVP infrastructure, and they are also the two areas where founders most commonly make mistakes. Authentication is not just a login screen — it is session management, token security, password reset flows, OAuth integrations, and, eventually, SSO for enterprise customers. Using a managed auth service like Supabase Auth, Clerk, or Auth0 eliminates the most dangerous security risks and saves weeks of development time. Billing is equally complex. Stripe is the undisputed standard for SaaS billing. It handles subscription management, failed payment retries, invoice generation, tax compliance, and customer portals. Do not build your own billing system. Do not delay adding billing to post-launch. Integrate Stripe before your first user signs up — even if you start with a free tier, the infrastructure needs to be in place.
Use a managed auth service — never build authentication from scratch
Supabase Auth, Clerk, or Auth0 are all production-ready options
Integrate Stripe before launch, even if you start with a free tier
Set up webhook handling for subscription events from day one
Implement a customer portal so users can manage their own billing
Protect all authenticated routes at the server level, not just client-side
Shipping your SaaS MVP and iterating fast
Shipping is the only thing that matters. A SaaS MVP that is 95% complete and sitting on a developer's machine has zero value. The moment you deploy to production and share it with real users is the moment your product starts generating real learning. Set a hard launch date — two weeks from today — and scope to fit within that date. Deploy to Vercel, Render, or Railway from a GitHub repository so that every code push triggers an automatic deploy. Set up error monitoring (Sentry is free for small volumes) so you know when things break. Set up analytics (Posthog or Mixpanel) so you know how users behave. Then share your product with the ten most relevant potential users you know and watch what happens. The feedback from your first ten users is worth more than another month of building.
Set a hard launch date and scope to fit — no extensions
Deploy from GitHub with CI/CD so every push ships automatically
Set up error monitoring before your first user signs up
Set up product analytics from day one — track activation, not just signups
Share with ten highly relevant users before going public
Treat every conversation with an early user as a research session
Ready to build your SaaS MVP?
We scope, build, and ship SaaS MVPs in days — with auth, billing, and your core workflow live from day one.