Since NAT gateway only have redundancy within a single Availability Zone(AZ), if I want to have a public/private pair of subnets in every AZ for the purpose of multi-AZ redundancy, should I have a NAT gateway in every AZ or I shouldn't?
Otherwise, if I have only one NAT, if the AZ goes down, all the subnets in all AZs go down with it, thus defeating the purpose of this multi-AZ deployment.