A framework that you can stay high level if you want and optimise when the rare but exceptional case arises on a particular route without splitting the process/

A framework that you can stay high level if you want and optimise when the rare but exceptional case arises on a particular route without splitting the process/resorting to C++ interop (with its own performance issues), or the risk of needing to rewrite due to performance to me is the big selling point. In a previous life I got some significant latency benefits by doing just that. I think its probably only gotten better with .NET 5.