Interesting, I didn't know it was C#.

One thing that immediately poked my eye is that it's also using MS SQL Server, and I am wondering why it'd be picked over various open source alternatives. My main guess is 'familiarity of the developers', but is there some MS SQL Server capability that is being used that is advantageous for the project? A cursory scan of the code makes it look like fairly simple SQL that would be perfectly at home in just about any RDBMS, and most of the others wouldn't come with the rather high licensing costs.

Don't get me wrong, I think MS SQL Server is a highly capable DB, I just don't see enough of a value add here to justify the price tag, in general.