The actual codebase itself may be pretty old so WebForms isn't a surprise - the SLN file indicates it was saved with Visual Studio 2010 (https://github.com/propublica/nyc-dna-software/blob/338a1b86...).
The actual codebase itself may be pretty old so WebForms isn't a surprise - the SLN file indicates it was saved with Visual Studio 2010 (https://github.com/propublica/nyc-dna-software/blob/338a1b86...).