Issuu provides a distribution platform for print publications and viewers for a range of devices. Much like on YouTube, users can upload content and share links to a viewer that displays the content. Issuu has more than 11,500,000 publications, serves over four billion pages a month to 70 million unique monthly visitors, making Issuu one of the 600 most visited sites in the world. On average, 25000 new publications are added daily, and they are automatically categorized and fully searchable. The 7 million registered users can upload publications and create collections of their favorite publications found on Issuu and share them with other users. This talk will provide a high-level overview of the Issuu architecture by tracing the lifecycle of a publication. How does the upload process work, how does automatic categorization work, how does a publication become searchable, what happens in publication discovery and consumption, etc. Keywords: Scalable architectures, functional programming, statistical analyses, programming in the large, cloud computing, Amazon EC2, message bus (amqp/rabbitmq).