The developers are the new idols of innovation, at the heart of the emergence of new technological objects (drones, 3D printers, biotechnologies, etc.) and of new uses. Often hosted in the renewed basements of enterprises, sometimes hackers, they share their time between their day job and their side project, and go beyond the standard norms of management and the classical division of labour. Their skills don’t come from a standard education, they are acquired progressively, through their own exploration of new technologies. Paris Chrysos tells the story of developers, decrypts their action mode and their way of thinking, and reveals the new rules of innovation. The author shows that the developers are the forerunners of a forward-thinking culture of work. He explains their role in the new economy and how they undertake a non-standard and creative process to manufacture better solutions or to project new technological dreams.