Dave is the primary architect of Ersatz and an expert in deep learning and neural networks. He speaks regularly on the topic and is the organizer of the San Francisco Neural Network Aficionados meetup group.
Ersatz came out of his frustration with existing machine learning tools. Everything was so... verbose. Sometimes a graphical interface really is the best way to do something, but there wasn't a particularly good graphical interface for machine learning, let alone deep learning. New software could fix that, and it would be web-based. Ersatz announced their beta in January 2013. In February 2014, it was spun out to Ersatz Labs.
As the product developed, Ersatz added data wrangling functionality (mostly due to user requests) and improved the API (always a good idea). It's still early days for Ersatz, but the product is the most full featured and stable product of its kind--web based machine learning APIs--available today.