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

   • Cold tea on a construction site. Buying scripts. Freelancer roulette.
   • Key fact: First version of 24ad.info launched with a Laravel codebase I didn’t understand.

2. The Expensive Lesson

   • Freelancers who vanished. Databases with no indexes.
   • Key fact: Server blacklisted after bots sent nearly a million spam emails through an unprotected contact form.

3. Learning by Fire

   • SSH sessions ending in permission errors. Testing Nginx, Apache, LiteSpeed—finally landing on Caddy.
   • Key fact: Used server snapshots instead of Git for two years.

4. The Attack

   • 3am alert. CPU at 100%. The birth of Sentinel from that chaos.
   • Key fact: First version was a Python cron job checking disk usage and services.

5. The Pivot

   • Discovering Claude. Rewriting everything in React 19 + tRPC.
   • Key fact: Rewrote breathtime.info in 6 hours—something impossible a year prior.

6. Where I Am Now

   • 5 live products. Still coding after construction shifts.
   • 283,103 attacks blocked by Sentinel — all-time
   • Free ebook available: fixflex.co.uk/ebook.html
   • "I don't know programming languages at expert level. I don't need to. I imagine, describe, verify — AI codes. I decide." ---

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, OVH, 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