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:
-
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.
-
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
Top comments (2)
The construction-worker framing is great and not just a hook - trades thinking actually transfers really well to shipping software. You already understand sequencing (you can't drywall before the framing), measure-twice-cut-once, that the unglamorous stuff (foundation, wiring, plumbing) is what the whole thing stands on, and that "done" means it passes inspection, not "it looks finished." Those are exactly the instincts most CS grads have to learn the hard way. A CS degree teaches theory; building and shipping teaches the thing that actually matters, and you came in already knowing how to finish a job.
The part where this gets genuinely accessible now: the "boring foundation" of a SaaS (auth, payments, deploy) used to be the wall that stopped non-CS builders, and that's exactly the wall I'm trying to remove. I build Moonshift - it takes a prompt to a deployed SaaS on your own GitHub + Vercel, with the boring structural parts wired as verified defaults, so you can focus on the part you understand (the product, the customer) instead of the plumbing. First run's free, no card - genuinely built for exactly the "I have the idea and the work ethic, not the CS degree" builder. Love this post. What are you building, and what part of the "foundation" tripped you up most coming from the trades? I'd bet auth or deploy, that's where everyone stalls.
Great analogy extension — "done means it passes inspection, not it looks finished" is exactly it. That's the instinct that saved me more than any tutorial.
Honestly though, auth and deploy weren't what tripped me up most. The thing that nearly killed me was security — the unglamorous wiring you don't see until it fails. I left a contact form with no rate limiting and a bot fired nearly a million emails through it before I noticed; got the server blacklisted. Deploy you can learn in a weekend. Knowing what a hostile internet does to an exposed endpoint, and building for that from the start — that was the real wall. It's literally why I ended up building a server monitoring tool.
Right now I'm running a few things: a classifieds platform (24ad.info) and that monitoring tool. Funny how the "plumbing" became the product. Will check out what you're building — the foundation-as-defaults idea is a real pain point.