Thanks for that! Armed with the advice I'll take another look. Though I think that, on the face of it, completely leaves out my interest in compilers, program

Thanks for that! Armed with the advice I'll take another look. Though I think that, on the face of it, completely leaves out my interest in compilers, programming languages and toolchains, and in kernels/devices/embedded systems, which are a big part of my work in practice. Maybe the "System" in "System/Devops" covers that, but those two are a peculiar match: I've might quite a few devops workers who consider software development to be slightly outside their knowledge, and something like C or C++ programming to be "very advanced". I find it peculiar that anyone can do devops without being a competent programmer but hey, it takes all sorts!