> That doesn't really seem like an example, since the whole thing doesn't run one machine.
It is an example. It shows you how you can run a service that issues a few hundred million SSL certs a year off relatively few pieces of hardware, i.e. no need to go drinking the cloud Kool aid.
There will never be a "perfect" example. The overall point here is demonstrating that the first answer to everything doesn't have to include the word "cloud".
> The database alone has multiple machines.
As I said, and the blog says ... there is only one writer. The other nodes are smaller read replicas.
Which again shows you don't need to go with the cloud buzzword-filled database services.