one builder · every layer owned

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

Just me, a clear vision,
and AI doing the heavy lifting

I'm Slawek, the founder of FixFlex LTD — a one-person app development studio in West London. No agency, no team of contractors.

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.

View my projects →
Slawek — Founder FixFlex LTD
// 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.

// track record

Real results across shipped products

0active projects
0live platforms
0uptime
0performance gain (24ad.info)
// expertise

Technologies and platforms I work with

[web]

Web Development

React, Next.js, Vue, Laravel, Python, Flask. Modern frameworks for modern applications.

[mobile]

Mobile Development

React Native, Flutter, iOS, Android. Cross-platform solutions for maximum reach.

[cloud]

Cloud Infrastructure

AWS, DigitalOcean, Docker, Kubernetes. Scalable and reliable deployments.

[ai]

AI Integration

OpenAI, Claude, custom models. Intelligent features for your applications.

[data]

Database Optimization

MySQL, PostgreSQL, MongoDB, Redis. Performance tuning and scaling.

[sec]

Security

Fail2Ban, CrowdSec, UFW. Comprehensive security solutions.

// why work with me

One builder who ships
and owns every layer

  • [stack]

    Full-Stack Expertise

    Frontend, backend, database, deployment — I handle every layer myself, end to end.

  • [sec]

    Security First

    Security built in from day one — it's literally what Sentinel does. I follow best practices and keep your data safe.

  • [perf]

    Performance Optimized

    I optimise for speed and efficiency — your app stays fast and responsive (I got 24ad.info 35x faster).

  • [24/7]

    24/7 Support

    Ongoing support and monitoring — I'm the one who answers when you need help.

  • [local]

    Local West London

    Based in West London — I understand local needs and can meet in person.

  • [oss]

    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.

Get in touch