Conceptual, architectural explainers — how a subsystem actually works underneath.
How FreeBSD moves changes through CURRENT, STABLE, releng branches, freezes, release candidates, and supported production releases.
How FreeBSD ZFS pools, vdevs, datasets, snapshots, replication, scrubs, ARC, and boot environments behave in real operations.
Trace a modern Linux boot across firmware, boot manager, kernel, initramfs, real root, and PID 1 with safe diagnostics for each handoff.
Understand cgroup v2 hierarchy, controller delegation, CPU, memory, I/O and PID controls, using safe systemd workflows and kernel evidence.
Understand eBPF programs, verifier, maps, hooks, BTF and CO-RE, privileges and operational risks without treating kernel execution as a sandbox.
Build, inspect, sign, load and remove a minimal out-of-tree Linux module inside a disposable VM with matching kbuild artifacts and safe rollback.
Compare SELinux label policy and AppArmor profiles through enforcement, logging, safe policy changes, containers and a denial-first audit workflow.
Understand Linux namespace types, ownership, lifetime and composition, then inspect containers without mistaking an isolated view for security.
Compare APT/dpkg, DNF4/DNF5/RPM and Pacman workflows, trust, transactions, upgrades and recovery without mixing incompatible repositories.
Read procfs and sysfs safely across PID, user, mount and network namespaces; inspect volatile kernel state without leaking secrets or changing hardware.