Hi 👋 My name is Mateusz.

I am a software engineer and IT leader based in Poland, with almost 20 years spent building digital products and the teams that keep them alive.

Right now I am measuring something most people only argue about: whether a design system changes what a coding agent actually writes. I built the system, ran the experiment against it, and published everything — including uncomfortable part.

The design system The experiment

Who am I

Three roles, one job: making good work possible.

Fifteen years moved me from writing the code, to leading the people who write it, to explaining out loud why any of it matters.

Engineer

A master's in computer science and 20 years of delivery across e-commerce, logistics, finance and TV/VOD. Front ends in Vue, Angular and React, with solid ground in backends, databases and cloud — and, lately, AI tooling folded into how I actually work rather than talked about.

Angular
React
Vue
Cloud
AI tooling

Leader

In lead roles since 2018, and these days I tie my career to people rather than to technologies. My approach is supportive and empathetic: build the conditions where a team can do its best work. Leading has taught me more about myself than any other role, and I keep working at it — listening, reading, training.

Engineering management
Team growth
Executive MBA

Educator & speaker

I share knowladge on social media covering hands-on engineering, leadership, software development and AI. I speak at conferences and events on the same subjects.

Conference talks
Writing

Design system

Built as infrastructure, then put under test.

A working design system, built end to end as platform infrastructure rather than as a component collection. Every layer below is public, versioned and verified on every pull request.

How it is built

Design source A Figma file is the origin of every value. Tokens are exported from it, not eyeballed from a screenshot.
Tokens Three enforced tiers — raw options, semantic decisions, component-private — built with Style Dictionary. The published CSS entry point exposes the decision tier only, so the boundary is enforced by the package rather than by a page in a wiki.
Components Fourteen standalone Angular components consuming those tokens, packaged with ng-packagr, versioned with semver, developed and documented in Storybook.
Verification Token contract tests, unit tests, interaction tests, automated accessibility checks and visual regression — the whole pyramid, on every change.
Distribution Two npm packages released by GitHub Actions, so consuming an update is an ordinary dependency bump.
Agent contracts A guide shipped inside the package, written for coding agents rather than for people, plus a token resolver exposed over MCP.

Is any of it measurable?

That last layer is the open question, so I am testing it. One specification, one application, several levels of the infrastructure above handed to a coding agent, and scorers committed before any run — how much of the system it actually uses, and what it writes when it has less. Raw data is published per run, including the comparisons that went against my own work.

The design system The experiment