We really liked the idea of spreading some sort of "human" load across a swath of users. The basic idea of doing something like drawing on a picture then sending it to another user lead us to focus on a more wide crowdsource with a more pertinent use-case. We use Rails and Postgres on the back end to keep track of user data, the "essay" they've submitted, and the chunks of that essay that we passed around to other users. The front end was built with Node using React and allows for providing feedback on individual piecing as well as putting your essay up for feedback.
We had never used rails before this event, and I personally had never dealt with React or Node (or a more traditional web-app).