There's a theory that the same person should not be both a Developer and an Operator for the same project - that crucial mental separation between Making someth

There's a theory that the same person should not be both a Developer and an Operator for the same project - that crucial mental separation between Making something and Keeping It Online gets too blurred when one person wears both hats. I've witnessed this in my own personal and professional projects. I guess it is a counter-argument to the DevOps/Agile philosophy.