We thought that at the SaaS I’m working at but AWS scheduled maintenance in our AZ and that led to significant downtime with nothing we could do about it, no compensation, nada. It was basically our fault because we didn’t use multi-AZ. I can’t remember if this was RDS or ECS but we figured if it could happen to one critical service in a single AZ, it could happen to another.

I think Proxy _is_ overkill and perhaps expensive for what it is. For a pg install, running pgBouncer isn’t difficult. But I guess that depends on whether you’re authenticating with IAMs, which doesn’t sound trivial with bouncer (it might be).

Multi-AZ is freaking awesome because the literal first 10 minutes I'm forced to give a shit about my RDS DB, its already a waste of money vs the monthly cost.