The Construction Worker’s Guide to Building SaaS Without a CS Degree

This morning, I checked Sentinel’s dashboard—283,103 blocked attacks. Four years ago, I couldn’t even spell "SSH."

I’m Slawomir Luzny, founder of FixFlex LTD in West London. I still wake up at 5:45am for construction work. I still code at night. And I just published a free ebook about how I built 5 live SaaS products without a computer science degree.

Why This Exists

In 2021, I was a construction worker with an idea for a classifieds platform. Zero coding experience. I did what everyone does:

1. Bought a ready-made script
2. Hired freelancers (who delivered half-working solutions)
3. Watched bots attack my server while Cloudflare shrugged
4. Spent a year and a small fortune fighting fires

Then I made a decision: Either I learn this myself, or the project dies.

What’s Inside the Ebook

6 chapters of hard-won lessons:

1. The Idea
2. Cold tea on a construction site. Buying scripts. Freelancer roulette.

3. Key fact: First version of 24ad.info launched with a Laravel codebase I didn’t understand.

4. The Expensive Lesson

5. Freelancers who vanished. Databases with no indexes.

6. Key fact: Server blacklisted after bots sent nearly a million spam emails through an unprotected contact form.

7. Learning by Fire

8. SSH sessions ending in permission errors. Testing Nginx, Apache, LiteSpeed—finally landing on Caddy.

9. Key fact: Used server snapshots instead of Git for two years.

10. The Attack

11. 3am alert. CPU at 100%. The birth of Sentinel from that chaos.

12. Key fact: First version was a Python cron job checking disk usage and services.

13. The Pivot

14. Discovering Claude. Rewriting everything in React 19 + tRPC.

15. Key fact: Rewrote breathtime.info in 6 hours—something impossible a year prior.

16. Where I Am Now

17. 5 live products. Still coding after construction shifts.
18. Key fact: 99.5% uptime across 3 operational platforms.

The Tools That Actually Worked

• AI: Claude for reasoning, GPT for code snippets
• Stack: React 19, TypeScript, tRPC, Node.js (after abandoning Laravel)
• Infrastructure: Caddy server, DigitalOcean droplets, Fail2Ban
• Security: Sentinel (born from my own bot attacks)

Who This Is For

• Non-technical founders tired of outsourcing to agencies
• Bootstrappers who need to move fast without a dev team
• Anyone who thinks you need a CS degree to build SaaS

How to Get It

1. Free download: [Gumroad link]
2. Email access: fixflex.co.uk/ebook.html

No fluff. No "10x productivity" nonsense. Just the exact steps that took me from construction site to 5 live products.

Final note: If you’re waiting until you "know enough" to start—stop. The knowledge follows the doing.

"I don’t know programming languages at an expert level. I don’t need to. I imagine, describe, verify—AI codes. I decide."

— Slawomir Luzny
Founder, FixFlex LTD • West London