Writing this book has been fun, eye-opening, surprising, and occasionally frustrating. Thank you to all the people who have told me their remarkable stories, answered far-reaching and sometimes daft questions one-on-one and in open forums, and opened up new avenues for me to explore as I descended deeper into the rabbit hole. Both before and during the writing process I learned a huge amount from long conversations, inspiring speeches, roundtable discussions, chats over beer, and lengthy message exchanges with hugely talented blockchain practitioners from all corners of the world. I am incredibly grateful to all of you for taking the time to answer questions and tell me about your work, and for checking the accuracy of how our conversations are reflected in this text. Thanks to Gabby Dizon, Patricia O’Callaghan, Alex Amsel, Adam Clarey, Paul Miller, Rachel Wolfson, Anne Puck, Dylan Jones, Dan Lyons, Caitlin Long, Tyler Lindholm, Joshua Ashley Klayman, Ian Cornwell, Mark Bell, Martin Bartlam, Kim Cope, Jeremy Gardner, Tom Kysar, Hélène Stanway, Ghanshyam Patil, Mike Smith, Ant Stevens, Adryenn Ashley, Hartej Sawhney, Mariam Turashvili, Steve Schneider, Anne Ahola Ward, Daniel Doll-Steinberg, Tonya Evans, Corey Segall, Shontavia Johnson, Graham Richter, Helen Disney, Genevieve Leveille, Terence Eden, Rich Julien, Jeff Hasselman, Kapil Dhar, Aad van Moorsel, Holly Burgess, Josh Edwards, Thomas Power, Jonny Fry, Andreas Antonopolous, Marguerite deCourcelle, Emily Rose Dallara, and Akane Yokoo. Special thanks to Alison Shaw, Paul Sitoh, Steve Blanks, David Morton, and Joanne Rout for proofreading and suggesting changes, additions, and clarifications. I’ve also had a lot of encouragement along the way from friends, colleagues, the team at Business Expert Press, and of course, my family. My thanks and love to Xavier, Gaelle and Loïc for your patience and support, always.