Construction worker by day. SaaS builder by night.
I started with an idea and zero programming knowledge. Today I build real, working products with AI as my development team — I imagine, describe and verify; AI writes the code, I make the decisions.
Who I Am
I'm Slawek, the founder of FixFlex LTD — a one-person app development studio in West London. No agency, no team of contractors. Just me, a clear vision, and AI doing the heavy lifting.
I build and run everything myself: server-protection tools like Sentinel, the 24ad.info classifieds platform, breathtime.info, the open-source Project Brain and more. Full-stack code, cloud infrastructure, AI features and database tuning — all shipped solo.
My edge isn't memorising syntax. It's knowing exactly what I want, describing it precisely, and verifying every result until it's right. The AI is fast — the judgement is mine.
My Story
The Prompt Engineer from the Construction Site
Four years ago I was a regular construction worker with an idea for a classifieds platform and zero programming knowledge.
I bought a ready-made script, hired freelancers, paid good money and got half-working solutions. Bots attacked my server, databases degraded, Cloudflare didn't catch everything. One "expert" after another — none of them understood what I actually needed.
After a year of fighting windmills I realized: either I cut costs to the minimum or this project will never launch.
I started from scratch. With AI help I found free alternatives to cPanel, cheaper servers and free tools. I learned PowerShell, SSH and Webmin. I pasted code into chat windows and tested on a live server — because I couldn't even set up a local dev environment. Instead of Git I made server snapshots.
Then I found Windsurf. And later Claude. That changed everything.
I started building for real. I made thousands of mistakes — AI fixed one thing and broke another. I tested Nginx, Apache, LiteSpeed, Varnish, H2O until I chose Caddy and built a stable foundation on it.
I knew that before adding AI features to my app I had to fix the bots and security first. That's how Sentinel was born — my server guardian that first protected my own projects, then became a product I could sell to others.
Along the way I completely abandoned Laravel and PHP. I rewrote 24ad.info from scratch on a modern stack — React 19, TypeScript, tRPC, Node.js. I rewrote breathtime.info in just 6 hours. Everything is faster, cleaner and smoother.
I still wake up at 6am for construction work. I still code at night.
"I don't know programming languages at an expert level. I don't need to.
I imagine, describe, verify — AI codes. I decide."
FixFlex is the result of that journey: from a construction worker with an idea to someone who builds real, working SaaS products using AI as his development team.
My Expertise
Technologies and platforms I work with
Web Development
React, Next.js, Vue, Laravel, Python, Flask. Modern frameworks for modern applications.
Mobile Development
React Native, Flutter, iOS, Android. Cross-platform solutions for maximum reach.
Cloud Infrastructure
AWS, DigitalOcean, Docker, Kubernetes. Scalable and reliable deployments.
AI Integration
OpenAI, Claude, custom models. Intelligent features for your applications.
Database Optimization
MySQL, PostgreSQL, MongoDB, Redis. Performance tuning and scaling.
Security
Fail2Ban, CrowdSec, UFW. Comprehensive security solutions.
My Track Record
Real results across the products I've shipped
Active Projects
Currently developing and maintaining multiple applications
Live Platforms
Production applications serving real users
Uptime
Reliable infrastructure with high availability
Performance Gain
Optimized 24ad.info for 35x speed improvement
Why work with me?
What you get from one builder who ships and owns every layer
Full-Stack Expertise
Frontend, backend, database, deployment — I handle every layer myself, end to end.
Security First
Security built in from day one — it's literally what Sentinel does. I follow best practices and keep your data safe.
Performance Optimized
I optimise for speed and efficiency — your app stays fast and responsive (I got 24ad.info 35x faster).
24/7 Support
Ongoing support and monitoring — I'm the one who answers when you need help.
Local West London
Based in West London — I understand local needs and can meet in person.
Open Source
I publish open-source work — like Project Brain, my persistent-memory skill for Claude Code.
Ready to build your next application?
Get in touch and let's talk about how I can help bring your idea to life.