30,000+ ZIP codes. 90+ metrics. No loading spinner.
We built a real-estate market-intelligence mobile app that turns official U.S. housing data into an interactive four-tier map — State, Metro, County and ZIP — with 90+ tracked metrics, rendered live on a touch-friendly map and responsive from the whole country down to a single ZIP code.
We led the mobile engineering end-to-end: architecture, data layer and the map itself.
30,000+ ZIP codes, each carrying dozens of metrics, on a device with a fraction of a server's memory.
Most map apps show a manageable number of points — restaurants, listings, stores. This app had to show every U.S. ZIP code simultaneously, each carrying dozens of statistics, on a mobile device with limited memory and no guarantee of a fast connection.
The map also had to feel instant: switching metrics, zooming from country to neighborhood, filtering by value range — all without a loading spinner. The 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?'
Four-tier map. Tiered data strategy. 90+ metrics. Zero per-metric infrastructure cost.
Four-Tier Geographic Map
State → Metro → County → ZIP — automatically switching resolution as the user zooms, rendered on self-hosted vector tiles. The right level of detail at the right zoom level, with no marker clustering.
Tiered Data Strategy
State, metro and county data fetched once and cached locally with a daily refresh. ZIP-level data — too large to ever fully cache — streamed live and scoped to exactly what's on screen.
One Rendering Pipeline, 90+ Metrics
Color coding computed on-device from live data, so switching from 'Home Value' to 'Population Growth' is instant — no new map style to load, no server round-trip.
Semantic GraphQL Layer
A Cube.js semantic layer powers both the map and a national leaderboard/ranking screen, plus downloadable PDF market reports — one data layer serving every surface.
Feed, Subscriptions & Push
A market-focused news feed, native in-app-purchase subscriptions, and a push notification system with multi-device support and a remote-triggered force-update safety net.
Responsive from the country down to a single ZIP.
ZIP Codes on Mobile
Every U.S. ZIP code rendered simultaneously — with dozens of statistics each — on a device with a fraction of a server's memory.
Metrics, Zero Per-Metric Cost
A single rendering pipeline supports 90+ tracked metrics with zero additional infrastructure per metric — adding a data point is a data change, not a map change.
Cold Start
Tiered caching cut cold-start loading to three small, bounded datasets — the unbounded ZIP layer never blocks the app from being usable.