It's a matter of delegating responsibility. The stack is too deep and too complex for any one person to understand. I have a good understanding of the Java lang

It's a matter of delegating responsibility. The stack is too deep and too complex for any one person to understand. I have a good understanding of the Java language and the JVM. At some point I have to trust the JVM engineers to get things right on all the platforms the JVM runs on. I have a rudimentary understanding of the Linux and BSD kernels and how they can impact certain parts of my applications. But I have zero knowledge of Windows. But I don't need to, because the JVM engineers do, and things Just Work (TM). I'm not smart enough to learn the intricacies of every platform, and thankfully I don't need to be. I guess you have similar issues with POSIX and the abstractions offered by high level programming languages? I assume you write some CPU specific assembly and understand all the possible failure modes of that hardware?