I think domain knowledge matters quite a lot. The Linux Kernel is beyond just knowing C, C is pretty simple. But Kernel hacking means knowing the Linux Kernel i

I think domain knowledge matters quite a lot. The Linux Kernel is beyond just knowing C, C is pretty simple. But Kernel hacking means knowing the Linux Kernel itself, which is very difficult if you want to do it at the high level (write complicated features and not just fixing some simple bugs). But I could say the same about projects like Django or Rails - how successful would Linus Trovalds be if we let him try write a few complicated new features to Rails? He doesn't know the Rails codebase or API, doesn't know Ruby probably, doesn't know web development that much. Even experienced Rails codebase maintainers have difficulties with adding complex features, it is usually a team effort. It's gonna be a lot for Linus to take in - months at a minimum and maybe more. But he is so talented he'll be able to do it for sure, much faster than a normal developer, but it still isn't trivial.