As others have pointed out, this is more about the age of existing buildings than the construction of the city, but it's pretty neat. About ten years ago when

As others have pointed out, this is more about the age of existing buildings than the construction of the city, but it's pretty neat. About ten years ago when we were working on Mapbox GL, I did a mobile-native viz like this to show off the vector tile tech. The blog post is still up (thankfully) which has a good bit of info on the data processing pipeline as well, ranging from Shapefile to GeoJSON to vector tiles on the backend to Swift on the frontend: https://medium.com/mapbox/visualizing-an-entire-citys-buildings-live-with-runtime-styling-453fe7e39ae6 https://medium.com/mapbox/visualizing-an-entire-citys-buildi... I always loved mirroring a phone to a large TV and showing this off at 60FPS. It was such fun tech to work on.