Before you start

This is the whole method. Everything you need to run your first Product Build Day is here, plus everything I wish somebody had handed me before mine: the prep, the scripts, the handouts, and what to do when it wobbles.

One promise, and only one. By the end of a single day, you and your team have working prototypes, real user reactions, and a decision someone with authority actually made. That is it. Not a better leadership style, not mastery of AI tools.

One day in, one decision out.

What changed since version 1. The method is the same. The book around it grew. Version 2 adds the two weeks before the day, the facilitation craft during it, a proper pitching chapter built on Jenny Lindblad's work, handout cards you can print for the room, copy-paste templates, and a troubleshooting guide. Version 2.1 adds the parallel build (Chapter 21) and the synthetic user testing that powers it. And because I lean on other people's research throughout, every page that borrows names its source at the foot. The people who did the work deserve the credit, and you deserve to check my claims.

How this book is marked. Some of this book is for your eyes only, and some of it is written to be handed over. Watch for two labels:

[FOR YOU ONLY]: facilitator material. Plans, scripts, fallbacks. Keep it.

[GIVE THIS TO THE ROOM]: participant material. Say it out loud or print it and hand it over. The printable versions are collected in Appendix A.

THE LICENCE. The method is free. Creative Commons BY-SA. Run your own day, remix it, teach it, charge for it if you want. Two things I ask you to keep on it: my name, Marcin Klimaszewski, and the Product Build Day name.

The playbook is not free. This file, the templates, the worksheets, the prompts. If a friend forwarded it to you, please grab your own copy at productbuildday.com. That sign-up is how I keep the work going.

Two small asks when you run one. Use the Product Build Day logo on your invite, your slides, and your wrap-up post; the kit is at productbuildday.com/media. And tell me about it! Tag me, send a photo from the room, share what your team built. I collect these stories and I pass them on, with credit to you.

You ran it, you get the credit.