Why use Flink at all?!

[mugwump]

Although this is a very nice example for connecting flink to elastic, I don't get the underlying assumption here: For what do I need Flink here? What's wrong about writing the actual rides into elastic and then use a geohashgrid to count by target-location?

Currently, the flink setup hardcodes the 100x100meters cell-size into the counts, simply pushing the rides into ES not only get's rid of a hefty piece infrastructure, but also allows more flexibility for querying, visualisations: You're basically using flink to destroy information that for other scenarios might still be useful.

I really do not want to be disrespectful of all the effort you put into this example, but I'm really trying to figure out, where flink fits into an architecture involving ES and where the boundaries between the two systems are...