An interactive map of the whole U.S. housing market
A real-estate market-intelligence app that turns official U.S. housing data into an interactive map — not listings, but the underlying market itself: home values, rents, inventory, and affordability trends for every state, metro area, county, and ZIP code in the country.
Users zoom from a national view down to a single ZIP code and see a decade of historical trends, national rankings, and 90+ tracked metrics, all rendered live on a touch-friendly map. We led the mobile engineering end-to-end — architecture, data layer, and the map itself.
Every U.S. ZIP code, on a phone
Most map apps show a manageable number of points — restaurants, listings, stores. This app had to show every U.S. ZIP code (30,000+) at once, each carrying dozens of statistics, on a device with a fraction of a server's memory and no guarantee of a fast connection.
The map also had to feel instant: switching metrics, zooming from country to neighborhood, and filtering by value range all without a loading spinner. The honest engineering question was never “can we build a map with data on it” — it was “how much can we responsibly hold in memory on a phone, and how do we hide the rest until it's actually needed.”
The right detail at the right zoom
Four-tier geographic map
State → Metro → County → ZIP, automatically switching resolution as the user zooms, rendered on self-hosted vector tiles — the right layer of detail at the right zoom level, no marker clustering.
A tiered data strategy
State, metro and county data is fetched once and cached locally with a daily refresh. ZIP-level data — too large to ever fully cache — is streamed live and scoped to exactly what's on screen.
One shared map, ninety views
Color coding is computed on-device from live data, so switching from “Home Value” to “Population Growth” is instant — no new map style to load.
A semantic GraphQL layer
Cube.js powers both the map and a national leaderboard/ranking screen, plus downloadable PDF market reports.
Feed, subscriptions & push
A market-focused news feed, native in-app-purchase subscriptions, and a push system with multi-device support and a remote-triggered force-update safety net.
Responsive from the country down to a single ZIP
Responsive at every zoom
Went from “can we even show this much data on a phone” to a map that stays responsive from the whole country down to a single ZIP.
Bounded cold start
Tiered caching cut cold-start loading to three small, bounded datasets — the unbounded ZIP layer never blocks the app from being usable.
Zero cost per metric
A single rendering pipeline supports 90+ metrics with zero incremental infrastructure per metric — adding a data point is a data change, not a map change.