“Posts are heterogeneous in form (video, images, audio, text) and consists of semi-structured data (e.g. a textual post has a title and a body, but the actual textual content is un-structured). Luckily enough, our users do a great job at summarizing the content of their posts with tags. As the distri…”— Tumblr Engineering, engineering.tumblr.comTagged: Engineering, Systems, Categorization, Tagging, NLP