So, most of this job right now is getting ready for the 2020 Census. The Census Bureau keeps a master list of every address in the country and mails out surveys-- if they don't know about an address, that household doesn't get counted. In NYC this is a huge issue because of how much new construction there is, how many people live in weird tiny apartments, etc. So what my department is doing is collecting address lists from various city departments and comparing them. They each have different strengths and weaknesses. For instance, the Department of Buildings knows about every building, even ones under construction, but doesn't always know how many units there are inside.
My project is getting a handle on "group housing" like prisons, nursing homes, dormitories, military barracks, juvenile homes, and other places of that nature. Apparently these are a big reason we can't just combine all the different address lists digitally-- the Post Office might record a dorm as 200 addresses, while the Department of Buildings records it as 1. So when comparing the numbers we got from different agencies it helps to know where these institutions are, which I'm collecting from a few different sources. Once I've done as much as I can from research, we will go out in person to blocks we can't figure out that have big discrepancies between the sources. That's the fun part.