Learn how computers really run your code
CPUs, memory, the Linux kernel, concurrency and storage, taught step by step for engineers who want to understand what’s underneath, not just which flag to set.
Numbered sections from simple to deep, a question answered at every step, and a summary at the end.
Packets, page faults, handshakes and lock acquisitions, one step at a time, with the reason for each.
Numbers come from programs run for the chapter, or they link to where they came from. Real kernel source, pinned.
The course
75 chapters in 8 parts, from the processor up to distributed systems, plus 8 interactive labs.
Build it yourself
A game engine, a browser, a kernel, Docker. Roadmaps for the projects that teach systems best, one milestone at a time.
Field notes
Real outages and bugs, told start to finish, each with a reproduction you can run.
Your request takes 41 ms on loopback, every time but the first. Two timers from the early 1980s are waiting for each other, and neither one is wrong.
The dashboard says the pod is using 1.6 of its 4 cores. The kernel says it was throttled in 118 of the last 300 periods. Both are right. They just measure different things.
Your container has at least five different memory numbers, they disagree by hundreds of megabytes, and the kernel, the kubelet and your Grafana panel each trust a different one.