A psychologist’s eye,
an end-to-end craft,
and AI that ships.
I’m Marcin, a lead product designer who stays close to the work. I read the behaviour behind the brief, carry work from first principles to shipped detail, and put AI to work where it helps—while the judgement stays human.
Selected work
A few pieces that show how I think end to end.
Full case studies are password-protected due to NDA. The password is included in my résumé.
Accounting Rules Navigator
Private case · password in résumé UnlockedGave finance teams one visual map to configure their own accounting rules — no IT in the loop.
Aptitude Design System
Private case · password in résumé UnlockedAptitude's first design system — one shared foundation that kept 5 dev teams and a doubling design team in sync.
Virtual Machines
Private case · password in résumé UnlockedWide-lens research that overturned three foundational assumptions before an expensive build.
About
I design for how people actually behave, not how briefs assume they do.
Before product, I trained in psychology. It taught me to watch what people do under pressure rather than what they say in a workshop, and to treat every interface as a small experiment in attention and trust.
I’m comfortable across the whole arc - framing the problem, shaping the system, and pushing the last few pixels until the thing feels inevitable. I don’t hand off the hard part.
I lean on AI for the repetitive middle: variations, audits, first drafts, boilerplate. The hours go to judgement, not production, and the thinking stays mine.
Mostly I help teams decide. The best work I’ve done looks obvious in hindsight, because the arguments happened early, in low fidelity, where they’re cheap.
Contact
If any of this resonates, I’d like to hear what you’re working on.