A working reference
A growing library of courses on the systems everything else is standing on — new courses added over time, each written in dependency order, with an interactive model in every chapter rather than a diagram of one.
Every course stands on its own, but real systems overlap, and the library is cross-referenced wherever one course genuinely explains a layer underneath — or beside — another. Kubernetes resource limits point down to the cgroups that enforce them; pod termination points down to signal handling; kube-proxy points down to netfilter. Security threads sideways through nearly everything. Follow the ↗ markers when you want the layer underneath, or the concern running across the one you are reading.
As the library grows, so does the map between courses — each new one arrives already wired into whatever it touches, not bolted on afterward. If you are starting from scratch today, Linux Internals Part III is still the most useful thing to read before Kubernetes Internals — namespaces and cgroups are what a container actually is, and everything Kubernetes does with pods is a consequence.
Progress is tracked separately per course and stored in this browser. Every chapter prints cleanly to PDF.