By Ari, Rong, and Albert.
The majority of the Mongo code refactoring was done as a group in class. We editted the code together on Albert's machine and then Ari and Rong pulled and ran the editted code to check for errors. This process was repeated over and over again until we found no errors. This is the reason for the slew of tiny, rapid, commits by one person (Albert) as we'd get about a commit a minute from tiny changes in the code as everyone suggested solutions to test.
Usernames and passwords are stored on a local text file and are lightly encrypted (we think).
A mongo database called Main is used to store all posts, each of which also stores its comments.