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:
- Bought a ready-made script
- Hired freelancers (who delivered half-working solutions)
- Watched bots attack my server while Cloudflare shrugged
- 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:
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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.
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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.
-
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.
-
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.
-
The Pivot
- Discovering Claude. Rewriting everything in React 19 + tRPC.
- Key fact: Rewrote breathtime.info in 6 hours—something impossible a year prior.
-
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
- Free download: [Gumroad link]
- 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
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