geomesa VS sample-data

you could help dockerizing geomesa with/on Cassandra https://www.geomesa.org/ Currently its only dockerized with accumulo

If you really need to scale beyond what Postgres/PostGIS can handle, then you might want to check out GeoMesa[1], which is (very loosely) "PostGIS for HBase, Cassandra, or Google BigTable".

That being said, you may not need it, because Postgres/PostGIS can scale vertically to handle larger datasets than most people realize. I recommend loading your intended data (or your best simulation of it) into a Postgres instance running on one of the extremely large VMs available on your cloud provider, and running a load test with a distribution of the queries you'd expect. Assuming the deliberately over-provisioned instance is able to handle the queries, you can then run some experiments to "right-size" the instance to find the right balance of compute, memory, SSD, etc. If it can handle the queries but not at the QPS you need, then read replicas may also be a good solution.

[1] https://github.com/locationtech/geomesa

We (StatsBomb) make a bunch of stuff available at:

https://github.com/statsbomb/open-data

Interesting stuff from Metrica too:

https://github.com/metrica-sports/sample-data

There are other less legit sources that you may be able to work out for yourself. :)