Other things I’ve written:

Modern LaTeX , a (very!) short book on learning LaTeX without getting wrapped up in 1980s tech.
Sources at https://github.com/mrkline/modern-latex

What every systems programmer should know about concurrency, a brief primer on the topic. Sources can be found on Github and Gitlab.

Comparing Floating-Point Numbers is Tricky (Post version here, LaTeX sources here)

C++ on Embedded Systems (Post version here, LaTeX source here)

TeX: A tale of two worlds (Post version here)