>citus is a bit out of date, now mostly native azure not flexible at all
>neon has not released all of their kubernetes operator so its not fully open source yet
> Crunchy is just a kubernetes operator for HA postgres. but they are working on a cool thing to natively use IceBerg as FDW. But their attitude is that this serverless separation of compute and storage is not the right approach for the primary operational data store
At very first glance this would be much closer to neon, with the separated storage and compute.
Crunchy Postgres for Kubernetes is great if you're running Postgres inside Kubernetes, but is more of standard Postgres than something serverless. Citus also not really serverless at all, Citus is more focused on performance scaling where things are very co-located and you're outgrowing the bounds of a single node.
Neon has a consensus cluster of >=3 WAL storage servers using local storage that is not scale-to-zero. Only with multitenancy can you amortize it to scale-down-to-not-much.
It's not clear to me that kiwicopple's work horizontally scales compute, ever. It seems it has to be just one server, and if you ran multiple they'd corrupt the S3 storage.
[1] https://neon.tech / https://github.com/neondatabase/neon
[2] https://access.crunchydata.com/documentation/postgres-operat... / https://github.com/CrunchyData/postgres-operator
[3] https://www.citusdata.com / https://github.com/citusdata/citus