The "Designing Data Intensive Applications" book is a trade paperback textbook authored by Martin Kleppmann and published by O'Reilly Media, Incorporated. It is focused on the subject area of computers and caters to adult learners and those in further education. The book covers advanced topics related to designing reliable, scalable, and maintainable systems in the field of computer science. Written in English, this textbook presents big ideas behind data-intensive applications, making it a valuable resource for those looking to deepen their understanding in this area.