In 2008 Satoshi Nakamoto published a white paper proposing a peer-to-peer electronic cash system, which led to the development of blockchain infrastructure, cryptocurrencies and NFTs. These subjects remain opaque to many. In Proof of Work, photographer Danny Franzreb documents the physical places and people connected to this digital realm. During the boom phase of cryptocurrencies between 2021 and 2022, he visited miners, investors and fortune seekers, photographing locations that include basement mining operations, industrial mining farms, installations, cooling units, cable forests and industrial ruins in Russia, as well as high-tech factories with sustainable production in Sweden. Published by Hartmann Books in 2023, the book presents 72 images across 176 pages in a 21 × 29 cm hardcover format. It includes texts by Holly Roussell and Anika Meier, with design by Nicolas Polli, and appears in a German/English bilingual edition. Roussell and Meier are credited as authors of the accompanying essays, not as photographers; their texts complement Franzreb’s images without replacing the photographic work at the book’s center. The project traces the material weight of an often abstract subject: servers, energy use and improvised architectures, alongside the people who bet on digital currency’s future. Franzreb’s practice explores the transformative effects of modern society, and here he turns his attention to a subculture that often remains hidden in plain sight. Proof of Work offers a grounded, place-based look at a subject frequently discussed in abstractions, making it relevant to collections focused on technology, economics and contemporary documentary practice.