And yet you have no contact info in your profile...
There's also the obvious risk with even using a single PaaS running on multiple IaaS clouds. If your account with the PaaS gets hacked, or they get acquihired, or whatever, you can be screwed too.
Figuring out exactly where to have redundancy in your business is hard. Especially because building something to be redundant imposes costs (more expensive, slower development) and sometimes itself is the cause of outages (lots of hilarious failover-related failures have taken down sites).
There's also the obvious risk with even using a single PaaS running on multiple IaaS clouds. If your account with the PaaS gets hacked, or they get acquihired, or whatever, you can be screwed too.
Figuring out exactly where to have redundancy in your business is hard. Especially because building something to be redundant imposes costs (more expensive, slower development) and sometimes itself is the cause of outages (lots of hilarious failover-related failures have taken down sites).