Your technology stack shapes your business. Pick a stack that scales with you, has a large community, and won't be obsolete in 2 years. This guide walks through the decision framework.
The One Rule That Matters
Pick a boring technology with a large community. Not the newest hottest framework—the one that's been battle-tested by 10,000+ companies and is here to stay. Why? Because you'll spend less time debugging, more time shipping. When you run into a problem, you'll find the answer. When you hire engineers, they'll know the stack. When you need help, you'll find it. Choosing an exotic stack (Rust for the backend, Svelte for the frontend, DuckDB for the database) is fun for engineers and terrible for business. You'll build slower, hire slower, and struggle with maintenance. Our recommendation: Next.js (full-stack), Supabase (database + auth), Stripe (payments), Vercel (hosting). This stack is good for 95% of SaaS products. There's a reason thousands of startups use it: it works, it scales, and it's not going anywhere.
Frontend: Next.js is the Default
Next.js is the standard for startups building SaaS products. Why? It's React (most engineers know it), has built-in routing and server components, handles deployment seamlessly on Vercel, and scales from day one. Alternatives: Vue (slightly smaller community), Svelte (newer, smaller), Remix (similar to Next.js). For your first SaaS, don't explore alternatives. Next.js is 95% as good as anything else and 5x more supported. Framework choice is 10% of your success. Team quality, product clarity, and market timing are 90%. Don't spend two months evaluating frameworks.
Backend: Serverless Wins
You don't want to run servers. Serverless platforms (AWS Lambda, Vercel Functions, Supabase Functions) handle scaling, monitoring, and scaling for you. With serverless, you pay per execution. 10 requests a month? $0.20. 1M requests? $200. It scales with your business and you never have to worry about capacity. Alternative: Traditional server (DigitalOcean, Linode, AWS EC2). You manage scaling, uptime, security. For a startup, this is a distraction. You're optimizing for unknown problems. Our recommendation: Vercel Functions for APIs (tightly integrated with Next.js, zero deployment friction) and Supabase Functions (PostgreSQL, easy database access). Pair them with a job queue (Bull, Temporal) for background tasks.
Database: PostgreSQL, Always
PostgreSQL is the SQL database. It handles relational data, JSON, full-text search, and complex queries. Thousands of SaaS products run on Postgres. Why not other databases? MongoDB is weaker for relational data (most SaaS has relationships). DynamoDB is AWS-specific lock-in. SQLite is great for solo projects but not multi-user SaaS. Our recommendation: Supabase (Postgres managed, includes authentication, storage, real-time subscriptions, and Row-Level Security for multi-tenant). If Supabase doesn't fit your needs, Render or Railway offer managed Postgres on their own infrastructure. Cost: Supabase free tier includes 2 databases, 500MB storage, and 2GB bandwidth. Scales to $100+/month at Series A size. Cheaper than managing your own servers.
Authentication: Supabase Auth or Clerk
Don't build authentication yourself. It's complex (password hashing, session management, CSRF tokens), risky (one bug is a breach), and boring. Supabase Auth comes with Postgres and includes email/password, OAuth (Google, GitHub, Apple), and passwordless magic links. It's free and integrated. Clerk is an alternative (slightly nicer UX, more SSO options) but costs $25+/month. For your first SaaS, Supabase Auth is sufficient. If you need enterprise SSO (SAML, LDAP), consider Auth0 or Okta. But don't add complexity until you have enterprise customers. Most early SaaS customers sign up with Google.
Payments: Stripe (Subscriptions Only)
Stripe is the default for SaaS subscriptions. Simple setup (one API call), reliable, and they handle PCI-DSS compliance for you. Use Stripe Billing for subscriptions. Don't build your own billing system. Stripe handles retries, dunning management (collecting failed payments), and upgrades/downgrades. Cost: 2.9% + $0.30 per transaction. For a $99/month plan, that's $2.99. Acceptable and standard. If you're doing marketplace payments or payouts, use Stripe Connect (more complex, but powerful). For simple SaaS? Stripe standard billing is enough.
Hosting: Vercel for Next.js
If you're building with Next.js, Vercel is the natural choice. Zero deployment friction (connect your GitHub repo, push, and deploy in seconds), edge caching (faster globally), serverless functions included. Cost: Vercel free tier covers up to 100GB bandwidth/month. Growth plan is $20/month. At scale, you pay for bandwidth. But bandwidth is your "good problem"—it means you have users. Alternative: AWS Amplify, Netlify. But if you're using Next.js, Vercel is simpler. For databases and serverless functions outside Next.js, use Supabase or AWS. But your frontend lives on Vercel.
The Stack Decision Tree
If building a SaaS with < 1M users expected: Next.js + Supabase + Stripe + Vercel. Ship in 4 weeks. This stack scales to Series B without architectural changes. If building a marketplace or multi-vendor product: same stack, add Stripe Connect. Same simplicity. If building AI-powered SaaS: same stack, add Claude API or OpenAI. No special infrastructure needed until you're processing millions of requests. If you already have infrastructure (AWS, K8s): don't rip it out. But if starting fresh, Next.js + Supabase is 10x faster to market. Don't optimize for a future that might not happen. Build for today with tools that scale to tomorrow.