The one thing that the author forgot or didn't realize to mention is: Test moving your environment between service providers in production. You should be able

The one thing that the author forgot or didn't realize to mention is: Test moving your environment between service providers in production. You should be able to failover from one provider to another, in a predictable way. You should actually do so every few months so that you're well versed in what needs to happen. If you practice this, you will be prepared in case the absolute worst happens.