I spent three and half years at Tumblr. Starting as a Product Engineer, pre-Yahoo, then became an Engineering Manager, and finally morphing into a Product Manager role.
I worked on a variety of different projects: creation tools, Optica (now Official) – the default theme, embeddable posts, reblog redesign, and many others.
Optica, now renamed Official, is the default theme that everyone is assigned when they create a Tumblr blog. It’s also the default mobile theme.
I worked closely with Tumblr's creative director to design and develop it - making it easy to configure but difficult to screw up.
It has an obscene amount of installs.
Embeddable posts are Tumblr posts that can be embedded on third party sites. I essentially re-created posts in a light-weight, fully responsive way, with all the interactivity you’d expect - like, reblog, etc.
A week after they were launched, Buzzfeed posted the Dress article, which was an embedded Tumblr posts. It’s the most viewed Buzzfeed article of all time (or at least it was at the time).
The mobile web version of Tumblr was a neglected child for a long time. I was put in charge of revamping it. To do that, I hired a small team of engineers and got to work.
I spend the last year of my time at Tumblr working as a Product Manager. My team, Identity, was focused mainly on personalizing and making Tumblr as creative as you are. We worked on a few huge projects (reblog redesign was years in the making), and our users loved it.