I Built a SaaS in 48 Hours Using Only AI Tools — Here's What Happened
Source: Dev.to
Introduction
Everyone talks about AI replacing developers. I decided to test it by giving myself 48 hours to build a fully functional SaaS product using only AI tools: Claude for architecture and code, Cursor as my IDE, v0 for the UI, and Supabase for the backend.
Goal
- No manual coding unless AI gets stuck
- Every decision goes through AI first
- Ship something real, not a toy project
Product Idea
I described the product to Claude: a simple tool that helps freelancers track time and generate invoices automatically.
Architecture (Claude)
Claude produced:
- Database schema (PostgreSQL via Supabase)
- API routes structure
- Authentication flow
- Component hierarchy
The architecture was solid—better than what I could sketch on a whiteboard in two hours.
Development Experience (Cursor + Claude)
Cursor with Claude autocomplete wrote about 80 % of the code.
Key insight: AI writes code fast, but you still need to understand what it’s writing.
Security Issues I Found
- Missing rate limiting on auth endpoints
- SQL injection vulnerability in search
- Exposed API keys in client‑side code
Without experience, I would have shipped all three to production.
UI Generation (v0)
v0 generated beautiful components, but connecting them to real data required manual work. AI‑generated UI is great for static pages; state management still needs a human brain.
Deployment (Vercel + Supabase)
Deployment was trivial. The AI helped write the CI/CD pipeline.
What AI Did Well
- Boilerplate code (saved ~60 % of time)
- Database queries
- CSS and styling
- Documentation
What AI Struggled With
- Complex business logic
- Security considerations
- Edge cases
- State management across components
Takeaways
- AI didn’t replace me; it made me 3× faster.
- Speed without understanding is dangerous.
- The developers who will thrive aren’t the ones who can write code fastest; they’re the ones who can evaluate AI‑generated code and catch what it misses.
- Learn to code first. Then learn to use AI.