My partner got a job in New York and I was trying to picture myself living there, which is different from wanting to live there, and also different from being able to. I had requirements — real space, not a marketed box; a neighborhood that isn't all white; a decent public school; a rent that is what it is — and together these formed a question nobody could answer, or nobody would. The data existed. Six agencies had it in six databases that had apparently never met. I asked Google. Google had opinions. I asked a broker. The broker had a sales pitch.

I didn't move. But I couldn't stop looking at the data.

375 datasets. Billions of records. Rat inspections, property transactions back to 1966, teacher retention rates, 311 complaints filed at 3am by people whose landlords won't fix the heat. Every piece of it public. The reason nobody had the full picture was not that it was hidden but that it was separated, and the separation was doing work.

How to talk about who makes the data and who gets to use it?

The city collects from its residents. Every complaint, every filing, every arrest. The people who use it systematically are developers, hedge funds, and political consultants. The residents get hearsay. The people most affected by housing policy have the least access to housing data. The people most policed have the least access to policing data. The information is public and the asymmetry is total.

I am not a data engineer. I built this the way you build anything when you don't know what you're doing — badly, then less badly. I connected the datasets to an AI and something shifted. It didn't interpret the data. It let me move through it. The city talked back in its own records. Not search results. Structure.

I fell in love with the data, which is embarrassing. Not as a business asset — as a civic material, the way you might care about public architecture. Data outside of business intelligence is almost untouched. That this surprised me is the problem.

Common Ground crosses what the city keeps separate. A mirror of public record, queryable by anyone, owned by no one. NYC first because NYC has the most extraordinary public data on earth. Any city that publishes records can be crossed.

People want data. Or more precisely: people want the feeling of not being lied to, and data is the closest approximation, though it is not the same thing.