Jul 28, 2017 · 1 min read
The beauty of spherical geometry and quad-trees beautifully implemented in Google S2 to solve geo-fencing. With spatial locality maintained by indexing the cells using Hilbert space filling curves, it is an elegant solution. Couple this with Redis and you have a winner that can keep track of even the most demanding applications. I would be surprised if Uber dispatch is not using S2 at this moment.