@cosmoz

I build things, break them, and figure out how to put them back together.

Paweł S. Piotrowski · Warsaw

$ whoami

Twenty-something years of writing code, breaking production, and slowly learning how distributed systems actually behave (it is rarely what the docs promise).

Started on PHP and MySQL somewhere around 2004. Drifted through Python, Django, JavaScript, Go, Java, a bit of Ruby when it was cool. Got hooked on the parts of the stack that hurt — Kafka, NoSQL, multi-DC, the place where latency lives. Helped push a few companies from monoliths to microservices when that was still an opinion, not a default.

Right now I spend most days elbow-deep in LLMs — prompts, tools, agents, embeddings, the messy plumbing that turns a model into a product. Less interested in the hype, more interested in what survives contact with real users.

Along the way I have led teams big and small, but the part I actually enjoy is the technical problem in front of me. Architecture, weird performance bugs, the surprising state diagram nobody drew.

$ stack --current

Python · Go · TypeScript · a soft spot for Linux · Kafka · Postgres · Redis · Docker · Kubernetes · AWS, GCP, a little Azure · LLM APIs (Claude, GPT, local) · pgvector and friends · whatever the problem actually needs.

$ ls ~/code

The interesting stuff lives in private repos — tools I am building for myself, products I am shipping, and a couple of small businesses in the making. I open-source pieces as they get ready to leave the nest.

$ cat ~/.notes

$ uptime

Cycling. Automotive. Sailing. Travel. Photography. AFK when I can.