About David Mar
Seeing what I can do with Claude Code
I'm not a software developer or engineer — I'm interested in seeing what I can do with Claude Code. This site is a mix of professional and personal projects, all built that way: I bring the questions, Claude Code does the building.
The part that's mine is the part that isn't code: choosing questions worth asking, finding data that can genuinely answer them, and deciding whether an answer holds up. Sometimes it doesn't — one card-market study failed its own structural control, and it's reported that way rather than quietly dropped. The nulls stay in.
The data is real and the pipelines run on my own machine: 32.8 million daily dealer quotes behind the card-market work, a 17-million-row civic database behind the SF atlas. Nothing here is a mock-up.
How these get made
Pick a question that has an answer
Curiosity is cheap; a question that data can actually settle is the hard part.
Go get the real data
Open city portals, dealer quote archives, public datasets — local-first, no toy data.
Report what didn't work
Failed controls and null results stay in. They're the most honest thing here.