Kozlowski Web applications
Modern and fast, with an Angular frontend, built accessibility-minded (WCAG-oriented). Runs in the browser, nothing to install for the user.
Software when no off-the-shelf product fits
Some workflows can't be forced into standard software: the form that mirrors your approvals, the internal tool that knows exactly your process. I build that software to measure, modern, fast, and in a way you understand and own afterwards. And because I run the servers underneath myself, I don't develop past your infrastructure.
What I build
APIs & backends
Cleanly structured with NestJS and PostgreSQL. The foundation your application runs on reliably and extensibly, no spaghetti that collapses at the first change request.
Workflow & approval systems
Requests, reviews, multi-stage approvals, with roles, server-enforced rules and a complete history. Exactly the kind of internal software no off-the-shelf product covers.
Real-time & operations included
Changes appear instantly, no reloading. And operations are part of the deal: Docker, HTTPS, on your server or hosted by me. I don't just hand over code, I hand over a running application.
Desktop apps
When a web app isn't enough: native desktop programs for Windows, macOS and Linux with Tauri. Lightweight, without heavy browser baggage, and with access to the operating system where it's needed.
Don't take my word for it, try it
No screenshots, no promises: real, running software with open source. The credentials are right on each login page, all data is made up.
- FlowGate, multi-stage request & approval workflow with roles, an enforced state machine and a real-time board (Angular, NestJS, PostgreSQL, WebSocket). Open demo · Source
- Quellwerk, ask documents in plain language instead of searching; the search runs entirely locally, an AI answer is optional (Python, FastAPI, RAG/embeddings). Open demo · Source
- SaaS backend architecture, multi-tenant backend with row-level security, domain-driven design and an event architecture; shows how to separate multiple clients safely on one platform. Architecture study (PDF)
And the AI question
Yes, I use AI as a tool, the way a carpenter reaches for a machine instead of a hand plane. It takes the routine off my plate and makes me faster. But the decisions (how something is built, what's secure, what fits your workflow) and the responsibility for them stay with me. Your data does not go into any AI. The tool helps me with code, not with your content. And AI is not a button that spits out finished software: demanding projects still take real time and care.
Got an idea in mind?
Describe it like a short brief, the more concrete, the better I can assess it. The initial consultation is free and without obligation.