Postgres on ECS Behind an ALB

Hi,

No, unfortunately not, since PostgreSQL uses a message-based protocol for communication supported over TCP/IP protocol, and the ALB it is a Layer 7 load balancer type, and that means that it only supports communication HTTP, HTTPS and gRPC protocols.

Thus, an NLB would be a most appropriate option, as it is a Layer 4 load balancer type, and supports TCP, UDP and TLS protocols.