A great deal of gratitude is due to all the developers who sat for interviews in order to contribute to this book. Their patience, expertise and colorful explanations make this book what it is.

Special thanks to the developers who answered my incessant questions with extra detail, and took the time to explain ancillary concepts, code and hypotheticals at great length: Jonathan Wegener, Loren Brichter, Brandon Walkin and AJ of Marketcircle; Dave Witonsky for his enthusiasm and Marco Arment for one giant cup of green tea.

Thanks also to Clay Andres for his perennial guidance, and Kelly Moritz, Douglas Pundick, Tracy Brown Collins, and Joachim Bondo for their hard work and careful consideration. Many thanks also to Austin Carr, whose quick transcriptions saved me from the woes of carpal tunnel.

Finally, thanks to my editors at FastCompany, Noah Robischon and Lynne d Johnson particularly, for accommodating the crazed schedule I adopted while writing this book.