Today I learned about the comprehensive 'Build Your Own X' repository containing tutorials for building everything from operating systems to databases, and discovered the Web Dev Junkie YouTube channel for modern web development tutorials.
Today I learned about Gary Bernhardt's humorous take on software development culture, the pstrings tool for examining process memory strings, and pytest's powerful test collection and filtering capabilities.
Today I learned about the Guile Scheme baseline compiler, Bartosz Milewski's Category Theory for Programmers, the classic SICP book, and the challenges of tracking running processes on Linux systems.