Relatively easy... though, and I may be out of date, you have to choose replication or sharding at any given level... so if you want horizontal scale plus redun

Relatively easy... though, and I may be out of date, you have to choose replication or sharding at any given level... so if you want horizontal scale plus redundancy, you will wind up with slightly more complexity. My experience trying to recover a broken cluster after 5 hours of Azure going up/down in series was anything but fun. Would have to test, but the library for this post may well work with CockroachDB if you wanted to go that route instead of straight PostgreSQL. I think conceptually the sharding + replication of other DBs like Scylla/Cassandra and CockroachDB is a bit more elegant and easier to reason with. Just my own take though.