Right up until the DNS fails

I am using ClouDNS. That is an AnycastDNS provider. My hopes are that they are more reliable. But yeah, it is still DNS and it will fail. ;-)

But how are you going to web scale it!? /s

Web scale? It is an _web_ app, so it is already web scaled, hehe.

Seriously, this thing runs already on 3 servers. A primary + backup and a secondary in another datacenter/provider at Netcup. DNS with another AnycastDNS provider called ClouDNS. Everything still way cheaper then AWS. The database is already replicated for reads. And I could switch to sharding if necessary. I can easily scale to 5, 7, whatever dedicated servers. But I do not have to right now. The primary is at 1% (sic!) load.

There really is no magic behind this. And you have to write your application in a distributable way anyway, you need to understand the concepts of stateless, write-locking, etc. also with AWS.