Using machine learning to predict what file you need next

As we laid out in our blog post introducing DBXi, Dropbox is building features to help users stay focused on what matters. Searching through your content can be tedious, so we built content suggestions to make it easier to find the files you need, when you need them. We've built this feature using modern machine learning (ML) techniques, but the process to get here started with a simple question: how do people find their files? What kinds of behavior patterns are most common? Starting with this basic understanding of the kinds of files users access, we built a system using a set of simple heuristics--manually-defined rules that try to capture the behaviors we described above.