Good thing we support HA as well: https://docs.pgdog.dev/features/load-balancer/
Load balancer with health checks and failover, works out of the box. :) Battle-tested at this point too, so could be worth a look.
That's great news! I'll bookmark this in case I'm forced to manage Postgres again.
I've extensively used Dynamo (internally at Amazon and externally) and even founded a DB startup with it at it's core. Boiling down scalability of Postgres vs Dynamo as it's written in blog is a bit terse. Dynamo scales writes horizontally with the keyspace, forever. Postgres simply can't, and no number of layers between the machines and the developer changes that. Sharding, pooling, Citus are all layered on top of an engine where a given row's writes still land on one primary.