How to Build a SaaS Tech Stack from Scratch: Complete Guide 2025

1. Frontend (What Users See)

This is your website or web app. Users interact with this. It needs to be fast, responsive, and work on mobile. Popular choices: React, Next.js, Vue.js, or even just HTML/CSS if you're keeping it simple.

My recommendation: Next.js (React framework) - best balance of features and ease of use

2. Backend (The Brain)

This processes requests, handles business logic, and talks to your database. You can build your own API or use serverless functions. Popular choices: Node.js, Python (Django/Flask), Ruby on Rails.

My recommendation: Node.js with Express or Next.js API routes - JavaScript everywhere simplifies things

3. Database (Where Data Lives)

You need somewhere to store user data, settings, transactions, etc. SQL databases (PostgreSQL, MySQL) are reliable and structured. NoSQL (MongoDB) is flexible but can get messy. Managed services (Supabase, PlanetScale) handle scaling for you.

My recommendation: PostgreSQL (via Supabase or Railway) - reliable, scalable, well-supported

4. Hosting (Where It Runs)

Your code needs to run somewhere. You can use traditional servers (AWS EC2), serverless (Vercel, Netlify), or platforms (Railway, Render). Serverless is easiest to start, platforms are easiest to scale.

My recommendation: Vercel for frontend, Railway for backend/database - minimal setup, auto-scaling

5. Authentication (User Login)

Users need to sign up and log in. You can build this yourself (complex, security risks) or use a service (Auth0, Supabase Auth, Clerk). Services handle security, password reset, social login, etc.

My recommendation: Supabase Auth or Clerk - easy to use, handles everything, good free tiers

6. Payments (Getting Paid)

If you're charging users, you need payment processing. Stripe is the industry standard (handles cards, subscriptions, invoices). Paddle is good for international (handles VAT). Chargebee is good for complex subscription logic.

My recommendation: Stripe - best documentation, most integrations, handles subscriptions well

7. Supporting Services

Email (SendGrid, Resend), monitoring (Sentry, LogRocket), analytics (Posthog, Mixpanel), file storage (AWS S3, Cloudinary). You don't need all of these day one, but you'll need them eventually.

My recommendation: Start with Resend (email) and Sentry (error tracking) - essential and affordable

Option 1: Next.js (React Framework)

Best for: Most SaaS products. Next.js is React with superpowers: server-side rendering, API routes, automatic optimization. It's what I use for all my projects now.

• ✅ Pros: Fast development, great SEO, excellent performance, huge community
• ❌ Cons: Learning curve if you don't know React, can be overkill for simple apps
• 💰 Cost: Free (hosting on Vercel is free for hobby, $20/month for pro)

When to choose: If you're building a web app (not just a website) and want the best balance of features and ease of use.

Option 2: Vue.js / Nuxt

Best for: Teams who prefer Vue's simpler syntax. Nuxt is Vue's equivalent to Next.js. Slightly smaller community than React, but still excellent.

• ✅ Pros: Easier learning curve than React, good performance, growing ecosystem
• ❌ Cons: Smaller community, fewer job candidates, less third-party support
• 💰 Cost: Free

When to choose: If your team already knows Vue, or you prefer Vue's template syntax over React's JSX.

Option 3: Traditional HTML/CSS/JS

Best for: Simple products, landing pages, or if you want maximum control and minimal complexity. Sometimes the simplest solution is best.

• ✅ Pros: No framework overhead, full control, easy to understand
• ❌ Cons: More code to write, harder to maintain at scale, no built-in features
• 💰 Cost: Free

When to choose: If you're building something very simple or you're not comfortable with frameworks yet.

Option 1: Next.js API Routes (Serverless)

If you're using Next.js for frontend, you can use API routes for backend. They're serverless functions that handle requests. Simple, integrated, and scales automatically.

• ✅ Pros: Same codebase as frontend, no separate server, auto-scaling, free on Vercel
• ❌ Cons: Cold starts can be slow, limited for long-running processes
• 💰 Cost: Free on Vercel (hobby), $20/month (pro) for more

When to choose: If you're using Next.js and your backend logic is relatively simple (most SaaS products).

Option 2: Node.js with Express

Traditional backend: you build an API server, deploy it, manage it. More control, more complexity. Good if you need long-running processes or complex background jobs.

• ✅ Pros: Full control, can handle complex logic, good for background jobs
• ❌ Cons: More to manage, need to handle scaling yourself, separate deployment
• 💰 Cost: $5-50/month depending on hosting (Railway, Render, AWS)

When to choose: If you need background jobs, WebSockets, or complex processing that doesn't fit serverless.

Option 3: Python (Django/Flask)

Python is great for data processing, ML, or if your team knows Python. Django is a full framework (lots of features), Flask is minimal (more control).

• ✅ Pros: Great for data/ML, Django has built-in admin, large ecosystem
• ❌ Cons: Slower than Node.js, more complex deployment, less common for SaaS
• 💰 Cost: Similar to Node.js ($5-50/month)

When to choose: If you're doing data processing, ML, or your team is Python-focused.

SQL Databases (PostgreSQL, MySQL)

Best for: Most SaaS products. Structured data, relationships, transactions, reliability. PostgreSQL is the modern standard.

• ✅ Pros: Reliable, handles relationships well, ACID transactions, mature tooling
• ❌ Cons: Less flexible schema, can be slower for very large datasets
• 💰 Cost: $5-25/month for managed (Supabase, Railway, Neon)

When to choose: For 95% of SaaS products. Start here unless you have a specific reason not to.

NoSQL Databases (MongoDB, Firebase)

Best for: Flexible schemas, rapid prototyping, or if your data doesn't fit relational models well.

• ✅ Pros: Flexible schema, fast for simple queries, good for prototyping
• ❌ Cons: No relationships, harder to query complex data, can get messy
• 💰 Cost: $0-25/month (MongoDB Atlas free tier, Firebase free tier)

When to choose: If you're prototyping quickly or your data truly doesn't fit a relational model (rare).

Option 1: Vercel (Frontend) + Railway (Backend/Database)

My top recommendation. Vercel for frontend (Next.js), Railway for backend and database. Both are simple, auto-scale, and have great developer experience.

• ✅ Pros: Minimal setup, auto-scaling, great DX, reasonable pricing
• ❌ Cons: Platform lock-in (but easy to migrate), can get expensive at scale
• 💰 Cost: $0-50/month to start, $100-500/month as you scale

When to choose: For most SaaS products. Best balance of ease and control.

Option 2: AWS (Everything)

The enterprise standard. Powerful, flexible, but complex. You can build anything, but you'll spend time learning AWS.

• ✅ Pros: Most powerful, most flexible, industry standard, scales infinitely
• ❌ Cons: Complex, steep learning curve, can be expensive if misconfigured
• 💰 Cost: $20-200/month to start, can scale to thousands

When to choose: If you need enterprise features, have AWS expertise, or are building at massive scale.

Option 3: Render / Fly.io

Similar to Railway: managed platforms that handle deployment and scaling. Good alternatives if you want options.

• ✅ Pros: Simple, auto-scaling, good pricing
• ❌ Cons: Smaller ecosystems, less documentation than Vercel/Railway
• 💰 Cost: $7-50/month to start

When to choose: If you want alternatives to Vercel/Railway or prefer their specific features.

Authentication: Supabase Auth or Clerk

Don't build auth yourself. It's complex, security-critical, and services do it better. Supabase Auth is free and integrated with their database. Clerk is purpose-built for auth with great UX.

• ✅ Supabase: Free tier generous, integrated with database, good docs
• ✅ Clerk: Better UX, more features, $25/month for production
• 💰 Cost: Free (Supabase) or $25/month (Clerk)

My pick: Supabase Auth if you're using Supabase, Clerk if you want the best UX and can afford it.

Payments: Stripe

Stripe is the standard. It handles cards, subscriptions, invoices, tax, everything. Best documentation, most integrations, reliable. Use it unless you have a specific reason not to.

• ✅ Pros: Best docs, most integrations, handles subscriptions well, reliable
• ❌ Cons: 2.9% + $0.30 per transaction (standard for industry)
• 💰 Cost: 2.9% + $0.30 per transaction, no monthly fee

Alternatives: Paddle (handles VAT for international), Chargebee (complex subscription logic). But start with Stripe.

Email: Resend or SendGrid

You'll need to send emails: welcome emails, password resets, notifications. Don't use your personal email—use a service. Resend is modern and developer-friendly. SendGrid is the established option.

• ✅ Resend: Modern API, great docs, $20/month for 50k emails
• ✅ SendGrid: Established, free tier (100 emails/day), $15/month for more
• 💰 Cost: $0-20/month depending on volume

My pick: Resend for modern projects, SendGrid if you want the free tier.

Error Tracking: Sentry

Things break. You need to know when and why. Sentry tracks errors, shows you stack traces, and alerts you when things go wrong. Essential for production apps.

• ✅ Pros: Best error tracking, great alerts, good free tier
• 💰 Cost: Free for 5k events/month, $26/month for more

Start with Sentry. You'll thank yourself when something breaks.

Step 1: Set Up Frontend (Next.js on Vercel)

1. Create a Next.js project: npx create-next-app@latest
2. Push to GitHub
3. Connect to Vercel (import from GitHub)
4. Vercel auto-deploys on every push

Time: 10 minutes. Cost: Free.

Step 2: Set Up Database (PostgreSQL on Railway)

1. Sign up for Railway
2. Create new project → Add PostgreSQL
3. Copy connection string
4. Use in your Next.js app with environment variables

Time: 5 minutes. Cost: $5/month.

Step 3: Set Up Authentication (Supabase Auth)

1. Sign up for Supabase
2. Create new project
3. Enable Auth in dashboard
4. Install Supabase client in Next.js
5. Add login/signup pages

Time: 30 minutes. Cost: Free.

Step 4: Set Up Payments (Stripe)

1. Sign up for Stripe
2. Get API keys (test and live)
3. Install Stripe SDK: npm install stripe
4. Create checkout session API route
5. Add webhook handler for subscription events

Time: 2-3 hours. Cost: 2.9% + $0.30 per transaction.

Step 5: Set Up Email (Resend)

1. Sign up for Resend
2. Verify your domain
3. Get API key
4. Install Resend SDK
5. Send welcome email on user signup

Time: 30 minutes. Cost: $20/month.

Step 6: Set Up Error Tracking (Sentry)

1. Sign up for Sentry
2. Create project
3. Install Sentry SDK: npm install @sentry/nextjs
4. Configure in sentry.client.config.ts
5. Test by throwing an error

Time: 15 minutes. Cost: Free (5k events/month).