3D Repo (http://3drepo.org), winner of the MongoDB Innovation Award, is a non-linear version control system that enables coordinated management of large scale 3D models over the Internet. It is currently the only cloud-based architecture able to support maintenance and transmission of 3D models and associated metadata as well as rendering on the scale required by the industry. With MongoDB we can deliver significant improvements in the engineering workflow that supports collaborative design not possible otherwise. Instead of architects, engineers and constructors sharing massive files in a costly and time consuming manner, they can simply point their web browser to a shared online 3D repository. With our system, all stakeholders are able to examine their projects virtually, even on mobile devices. During the presentation, we will demonstrate the management of massive 3D models in a repository built directly atop of MongoDB. We will also demonstrate our online web-browser viewer capable of rendering 3D models directly from the DB without the need to install any plug-ins or firewall exceptions.