Contact

One form, answered in a day

I am Marcin, and I read every message myself. Pick a topic so I know what to send back.

What you get back

For a team day, a plan and a price. For a seat, the next date and how to hold it. For anything else, a straight answer or an honest no. Within one business day, usually faster.

Recent rooms

21

Warsaw

22

Athens

4

Ionian Technologies

Three real days, with names and numbers. Read the case studies →

Rather use email?

[email protected]

Coming to a free evening? No form needed. Applications open per city on the events page →

In a hurry about a team day? Book the 15-minute call →

Based in Europe. Runs in English. Happy to travel.

Product Build Day. One day in. One decision out.

One-day, in-person vibe-coding build days where product people who do not code build working apps with AI tools and test them the same day. Tools like Lovable, Bolt, Replit, and Cursor do the typing. You do the thinking. Run in English across Europe by Marcin Klimaszewski.

Product Build Day // Pro, 490 EUR net per seat

A full day for senior product managers and product designers. Bring one real challenge from your own backlog. Before the day: a challenge-sharpening tool and a 1:1 call. On the day: design the cheapest validation test, build a working app with AI tools, test it with synthetic users and 16 senior peers, and leave with a working app at a URL plus a tested validation plan. Guarantee: no working app and no tested plan by 17:00, money back. Invoice with correct EU VAT, so it goes on the company card. 16 seats, by application, max 3 per company. Join the Pro list.

Product Build Day // Teams, from 5,900 EUR net

The same method inside your company. Up to 20 people build against your riskiest bets, with synthetic user testing included, real-user testing optional, a written debrief within a week, and a go, pivot, or stop decision made in the room. About 295 EUR a head at full size, one invoice, NDA-friendly. It starts with a free 15-minute fit call. Book the call.

Free community evenings, autumn 2026

Free evenings run three hours, usually 18:00 to 21:00. Copenhagen runs 17:00 to 20:00. They are free, in English, 16 seats per city: Amsterdam 14 September, Copenhagen 15 September, Stockholm 16 September, Berlin 17 September, London 8 October. See all events.

Proof

21 non-coders shipped 21 working apps in one Saturday in Warsaw. A museum set the brief and 22 people built the answer in Athens. Ionian Technologies built four product directions in one private day in Thessaloniki and tested them on the street the same afternoon. Both public days sold out.

The method, free

The Facilitator's Playbook has the whole method, Creative Commons BY-SA. Get the PDF. Prices for all three formats are public on /compare.

Contact

One inbox for everything: the contact form or contact@productbuildday.com. Answered within a business day.