140 Lessons • Self-Paced • From First Principles
Why Is My Code So Slow?
You've learned to write code that works. Now learn to write code that works fast. This course explains what's actually happening in memory, on the CPU, and across the network when your code runs.
Generated by Claude Code (Opus 4.6). There may be errors — all benchmarks are independently verified and documented.
This curriculum draws on decades of systems programming wisdom — from Jeff Dean's latency numbers to Google's performance engineering practices to the Linux kernel documentation. Where possible, every claim has been verified on the VM running this course (Intel Emerald Rapids, Python 3.11.14, GCC 13.3.0). Numbers that have changed since their original publication are noted with evolution notes, celebrating how rapidly both hardware and software continue to improve.
Python First
See concepts in familiar code
Then C
Understand what Python does internally
Then Assembly
See actual CPU instructions
Choose Your Path
Foundation
Start here if you're learning how computers work: sections 00–02, the 05 openers, 13, the 15 openers — then go where curiosity leads.
Core
The working engineer's track: everything Foundation, plus sections 03–08, 10, 12, 14, 17–22.
Advanced
The specialist cut: perf counters, memory ordering, lock-free, NUMA, SIMD, protobuf internals, GPU/distributed — sections 09, 11, 16, and the advanced-badged lessons throughout.
Foundation
Core
Advanced
140
Lessons
23
Sections
500+
Code Examples
∞
Insights