Which Tech Stack for Your SaaS? Next.js, PostgreSQL, Stripe and the Other Choices That Matter

Choosing a SaaS tech stack means deciding on the technologies that will carry your product for years: language, framework, database, hosting, payment and email services, monitoring tools. Developer debates about "the best stack" are endless; for a founder, the criteria are simpler. This guide presents them and details the choices we recommend, as well as those we avoid.

The five criteria that really count

1. Maturity: technologies proven in production, with an active community and regular updates.
2. Availability of skills: being able to hire, or hand the project to another team, in Morocco and elsewhere.
3. Development speed: ready-made components for standard needs (authentication, forms, tables).
4. Ability to grow: performance that keeps up with the number of customers without a rewrite.
5. Operating cost: hosting and third-party services proportionate to your revenue.

What shouldn't weigh: the "trendy" technology, a developer's personal preference, or the latest tool seen in a video.

Front-end: your SaaS interface

Next.js (based on React) and TypeScript form a very solid base for a SaaS application today: fast rendering, excellent SEO for public pages, typing that prevents whole categories of errors, a huge ecosystem of components. Tailwind CSS speeds up building a consistent interface. For teams already expert in another framework (Vue, Svelte, Angular), those choices remain valid; what matters is consistency and maintainability.

Back-end: logic and APIs

Two main options. Node.js with TypeScript (via Next.js itself or a framework such as NestJS) lets you share language and types between front-end and back-end, which reduces errors and costs. Python (FastAPI, Django) is preferable when the product relies heavily on data processing or AI. Both are mature, well documented and easy to hire for.

Database: PostgreSQL, unless there's a reason not to

PostgreSQL is our default recommendation for a SaaS: reliable, open source, fast, with features valuable for multi-tenancy (row-level security policies), search, JSON and even vector search for AI. Every major host offers it as a managed service. A tool such as Prisma or Drizzle makes migrations and queries safe and readable. NoSQL databases are justified for specific cases (very large event volumes, unstructured documents), rarely for the core of a management SaaS.

Hosting and deployment

• Managed platforms (Vercel, Netlify, Railway, Render, Supabase): deployment in minutes, automatic scaling, ideal to start.
• Classic cloud (European regions or Moroccan providers) with Docker: more control over data location and costs at scale.
• Automated deployment (GitHub Actions or equivalent): every validated change is tested then released without manual intervention.
• Separate environments: development, staging, production, with anonymised data outside production.

Third-party services not to reinvent

• Authentication: Auth0, Clerk or a self-hosted open source solution, for login, SSO and two-factor authentication.
• Payments: a local gateway, a merchant of record platform or Stripe depending on your markets (see SaaS payments in Morocco).
• Transactional email: Resend, Brevo or equivalent, for confirmations and invoices that actually arrive.
• Error tracking: Sentry, to see every production error with its context.
• Product analytics: PostHog or Mixpanel, to understand usage and roll out features gradually.
• Files: object storage (S3 or compatible) with signed, per-tenant access.

What about AI in the stack?

If your product includes AI features (assistant, smart search, summaries), add a model access layer (OpenAI, Claude, Gemini, Mistral or self-hosted open source models), vector storage (PostgreSQL with pgvector is often enough) and answer evaluation. We detail these building blocks on our AI agents page.

The most common stack mistakes

• Over-engineering: microservices, Kubernetes and complex queues for a product with ten customers. Start simple; the architecture grows in stages.
• Obscure technologies only the original developer masters.
• Building everything yourself (authentication, payments, email) instead of using proven services.
• No automated tests on critical journeys: every release becomes a risk.
• Secrets in the code and no separation between staging and production.

How a SaaS application is split

Whatever the stack, a well-structured SaaS separates five parts that evolve at different paces. The public pages (home, pricing, blog), optimised for search and conversion. The logged-in application, reserved for authenticated users, where the key journey lives. The API, which serves the application, integrations and, one day, your customers. Background processing (bulk sends, exports, synchronisations, heavy calculations), run through queues so the interface doesn't slow down. And the back office, for your team: accounts, subscriptions, support, metrics. Next.js can host the first three in a single project, while processing and the back office can start simply and be separated when volume justifies it.

What the stack costs to run at the start

Good news for a launch: most of the recommended services offer free or low-cost tiers that are more than enough for the first months, then usage-based billing. At the start, the main item is hosting the application and the database; email, monitoring and analytics remain marginal. Two precautions: enable budget-overrun alerts on every service, and avoid architectures that multiply billed components before you have customers. A SaaS with twenty customers doesn't need ten paid services.

When to depart from the standard stack

• Intensive real time (chat, simultaneous collaboration, GPS tracking): components dedicated to persistent connections and event streams.
• Native mobile app: React Native or Expo to share logic with the web, or native apps if sensors and performance demand it.
• Very large event volumes: a data warehouse or a specialised database alongside PostgreSQL.
• Document processing and AI: dedicated Python services, vector storage and continuous evaluation of results.
• Strict hosting constraints: on-premise infrastructure or a Moroccan host, with Docker and suitable deployment automation.

Questions to ask about the proposed stack

1. Why these technologies for our product, and not others?
2. How many developers master them in Morocco and internationally?
3. What happens if we change vendor: can the project be taken over?
4. Which third-party services are used, and what do they cost at a hundred, a thousand, ten thousand customers?
5. How are releases automated and tested?
6. Where is the data hosted, and can we change region or provider?

Our reference stack for a SaaS

Next.js, React and TypeScript for the application; Node.js or Python for specific services; PostgreSQL with Prisma; managed hosting or Docker on a European or Moroccan cloud depending on constraints; Auth0 or equivalent, a payment gateway suited to the market, Resend, Sentry, PostHog and GitHub Actions. It's the basis of our SaaS development projects, adapted to each product: we choose according to your constraints, not habit. To discuss the right stack for your project, contact us.