Courses
Short, interactive courses on the things I actually work with — Linux, containers, and the infrastructure underneath. Free, no signup, and your progress is saved in your own browser.
Linux Basics
The command line, from zero. Learn how the shell actually works, how to move around a filesystem, and how to read the permissions and processes that everything else in Linux is built on.
Shell Scripting
Write shell scripts that survive contact with a real machine. Variables, quoting, exit status, loops, functions, and redirection — in portable POSIX sh, the shell that exists in every container and CI image.
Containers From Scratch
Build a container by hand from the Linux primitives underneath it — namespaces, cgroups, chroot, veth pairs, NAT, and copy-on-write snapshots. No container runtime is installed at any point, and by the end the whole stack stops being magic.