video1.0<iframe src="https://www.loom.com/embed/4d37266a0a5143b3a2d5bd9e8c45e688" frameborder="0" width="1670" height="1252" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>12521670Loomhttps://www.loom.com12521670https://cdn.loom.com/sessions/thumbnails/4d37266a0a5143b3a2d5bd9e8c45e688-faf2154b9b827180.jpg449.219We worked on a project to let people put one folder inside of another. It was surprisingly tricky! This is mostly because it comes alongside a change to how our permissions model works. This talk goes over how our permissions model works, and then how we checked its soundness using model-checking software called Alloy.