But that's AFTER startup. I think this is a very nice pattern for servers. Do as much work as possible at startup time. Do anything that can fail, including allocating memory.

And then in the request path, be miserly about what you are willing to do. "Modern" web servers like nginx seem to be designed this way. Node JS's HTTP parser makes a point of not allocating any memory.

I think you'd be surprised how far this pattern can go.