[c7b]

If we were to start from security first, we would be asking questions like 'how can we make sure that new code is safe?'. Manual review is great, but we can likely think of some desirable invariants for program behavior that could be tested automatically, or even formally verified. Those would come at the very start. The entire mindset right now is that the existing code is probably unsafe and we'll ship fixes as we discover its vulnerabilities. Not immediately applying updates is seen as a kind of moral failure. All major OS and most software projects were developed with this mindset of crossing your fingers at launch and then changing the tires while driving. So much so that we think of it as the natural state of software. If you start from a base of verified code, the mindset shifts. Not that there are zero vulnerabilities guaranteed in the existing code, but you become a lot more suspicious of new code.