[Bedon292]

Very interesting. Used to do something similar for a project I work on. Used geohash based sharding, instead of complex curves like that. Worked great, but with recent advances in ES its no longer needed. They don't seem to mention which version of ES they are on, and would be curious how it has changed over time in their experience.

[realfun]

Same strategy can be applied regardless of ES version. ES6 does has index sorting and other optimizations, but not as good as pre-sharding for location based services, cases like Tinder.