What is the negative consequence of breaking the site for an hour? Is it "some people are a little annoyed", "nobody notices", or "customers start calling and are very upset" or even "customers file lawsuits"?
The amount of friction you add to the development velocity has to be proportioned to the potential downsides. A system that shows doctors xray images in the ER cant go down or people might die. A site like twitter can go down and slightly improve the life of its users. It sounds like you are recommending big company super risk averse solutions at a startup, which is just silly. Besides, staging environments never work, for a long list of reasons. You should be recommending continuous integration and a focus on proper unit tests.
The amount of friction you add to the development velocity has to be proportioned to the potential downsides. A system that shows doctors xray images in the ER cant go down or people might die. A site like twitter can go down and slightly improve the life of its users. It sounds like you are recommending big company super risk averse solutions at a startup, which is just silly. Besides, staging environments never work, for a long list of reasons. You should be recommending continuous integration and a focus on proper unit tests.