How Vantage Vancouver was built

Vancouver real estate has rich public data (BC Assessment annual valuations, parcel polygons, zoning) but it's scattered across CSV dumps, shapefiles, and government APIs. Vantage stitches it into a single map-first explorer where you can click any parcel, drill into a building, and inspect every strata title within it.

• Source: BC Assessment yearly roll (2016–2026), City of Vancouver parcel polygons, zoning bylaw shapefiles.
• Store: PostgreSQL 18 + PostGIS 3.6, hosted on Railway.
• Schema: a wide core.property_current table (last-known state per PID), core.assessment_yearly for time series, and core.site_events for subdivisions / demolitions / redevelopments.
• Lineage: a UUID per physical lot (lineage_id) groups strata titles and tracks parcels across PID changes.

BC Assessment doesn't link an individual condo PID to its parent land parcel via a foreign key. The bridge is spatial: each STRATA centroid is point-in-polygon joined to the LAND parcel that covers it (ST_Covers(land.parcel_polygon, strata.centroid)). That's how clicking 833 Seymour reveals all 374 strata titles inside Capitol Residences.

• Stack: FastAPI + Pydantic + SQLAlchemy Core, deployed on Railway.
• Endpoints:bbox parcel fetch with truncation guard, point-in-polygon lookup, address search, per-PID detail & history, per-lot timeline (events + aggregated values), per-PID units list.
• Performance: GiST spatial indexes on every polygon column, server-side bbox clipping, hard cap at 2,000 features per viewport request.

• Stack: Next.js 16 (App Router) + React 19 + Tailwind 4 + TanStack Query.
• Map: Mapbox GL JS with a custom geocoder constrained to Vancouver. Parcel layer renders as a thin outline; clicking fills it red and opens the inspector drawer.
• IA: two tabs per building — Building (aggregate story: total stack value, sparkline, lot events) and Units (per-strata drill-in with search). Single-PID lots hide the Units tab.
• UX details: recent searches in localStorage, Mapbox red-pin marker, default landing on a busy strata so the flow is visible on first paint.

• Sales data integration (LTSA or HouseSigma) for actual transaction prices.
• Permit pipeline overlay (approved + under-review developments).
• Comparables and price-per-sqft analytics.