Operating systems, infrastructure, emulation, and technical history.
Understanding the container/volume distinction that makes APFS different from older partition schemes, and using diskutil to manage volumes directly.
Resetting NVRAM and the System Management Controller — two different low-level resets solving different problems, on Apple Silicon and Intel Macs.
Using the same BSD packet filter that powers macOS's Application Firewall directly, for filtering the GUI's simple allow/deny-per-app model can't express.
Turning on macOS's built-in SSH server correctly, then hardening it beyond the default configuration with key-based authentication and restricted access.
Resetting stuck permission prompts, why an app sometimes doesn't re-ask for a permission it should, and what the TCC database actually is.
Starting, stopping, inspecting, and restoring Time Machine backups without the GUI — useful for scripting backups or diagnosing a stuck one.
Why Boot Camp stayed Intel-only on Apple Silicon, what native Windows would require, and how Microsoft now supports licensed Windows 11 Arm virtual machines.
How Apple spent a decade signaling the end of 32-bit app support before removing it in October 2019, making the transition smoother than it could have been.
Released September 25, 2017, High Sierra converted flash-storage Macs to Apple File System automatically — the biggest Mac filesystem shift in decades.
Released September 13, 2000 for $29.95, the 'Kodiak' public beta gave Mac users their first hands-on look at Aqua, preemptive multitasking, and protected memory.