How to build a SaaS app: choose the stack and first workflow

Define a small first release

Pick an observable outcome: a customer signs in, creates a project, invites a colleague if collaboration is essential, and completes the main task. Write down what is deliberately excluded. A large admin console, multiple paid plans, and a complex permission hierarchy do not belong in the first release unless the user journey requires them.

Separate the product data from identity records. For a team-based product, decide whether a record belongs to a user or to an organization. Make that decision before designing API handlers: retrofitting tenant ownership into already-shared data is harder than expressing it in the first data model.

Select a starting stack you can operate

For a TypeScript team, our SaaS stack combines a Next.js React application, PostgreSQL for relational data, an authentication choice, and a styling choice. Next.js is the application framework; React supplies UI components. Keeping these roles explicit makes substitutions easier to reason about.

Choose Better Auth when you want application-owned identity and can operate its supporting infrastructure. Choose Clerk when managed identity is a better fit for the team. For styling, Tailwind provides utilities, shadcn/ui adds editable component source with a Tailwind setup, and Mantine provides its own component and theme system. The stack starter lets you select these alternatives without silently including both auth providers.

Make data protection part of the first slice

A sign-in screen is not authorization. Check the session and the user’s permission to access a particular record inside the server operation. Do not rely on hiding a button, a client-supplied tenant ID, or a route redirect as the only protection for data.

Implement sign-out, session expiry handling, and useful failures alongside the happy path. Keep secrets in server-side configuration. Document environment variables with placeholders, and apply database changes deliberately to the intended environment.

• A signed-out request cannot read protected records.
• A signed-in user cannot read another customer’s records.
• Loading, empty, expired-session, and error states are usable.
• Logs avoid tokens, passwords, and sensitive customer content.

Add billing and operations deliberately

If the product charges customers, distinguish payment state from product entitlement. Decide what a customer can do during a trial, after cancellation, and when payment fails. Confirm the billing provider’s current event-verification and retry guidance before implementing its integration. The catalog stack is not a complete billing implementation.

Before accepting real customer data, establish backups, recovery ownership, error monitoring, and an account-support path. Estimate database, email, storage, and hosting costs at the expected usage level. These operational decisions matter more than adding another library to the stack.

Turn the plan into a build prompt

Open the TypeScript SaaS stack below, enter your product brief, and choose authentication and styling. Copy the generated prompt or download its Markdown file. Include the first workflow, tenant model, required integrations, and what should remain out of scope.

Ask the coding assistant to inspect the repository’s rules and verify current official setup instructions before installing packages. Review its data-access boundaries and validation results before treating the implementation as ready for customers.

Choose a stack and copy the starter prompt

• Customize the TypeScript SaaS starter
• Compare the open-source SaaS stack

Official sources

These are decision guides, not benchmark studies. The recommendations synthesize the linked documentation; verify current setup instructions and pricing before implementation.

• Next.js authentication guide
• Better Auth Next.js integration
• Clerk Next.js integration

Continue planning your build

• What tech stack should you use for your app?
• React stack choices: Better Auth or Clerk, shadcn/ui or Mantine?

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