The Unix underpinnings, frameworks, and platform security model behind Apple's desktop OS.
An operational account of Catalina's zsh default: which accounts changed, what stayed on Bash, and how administrators could migrate without breaking scripts.
Apple's multi-year push to deprecate kernel extensions for user-space System Extensions and DriverKit, and what changes when a driver runs outside the kernel.
Why traditional plain-text syslog couldn't keep up with modern macOS, and how unified logging's structured, activity-tracing design fixes that.
Why macOS's kernel is neither a pure microkernel nor a pure monolithic kernel, and what that hybrid design actually buys in practice.
The IPC framework behind most of macOS's privilege separation, built on Mach IPC but designed to make secure, sandboxed communication the easy default.
Building a real automation with both of macOS's built-in automation tools - when to reach for each, and how they actually relate to one another.
Reading macOS's unified logging system through Console - filtering the noise down to the specific process or subsystem actually relevant to a problem.
Viewing saved passwords, storing new items securely, managing certificates, and understanding how iCloud Keychain syncs credentials across devices.
Configuring Screen Time for app limits, content restrictions, and downtime scheduling - for a managed child account or your own usage discipline.
Launched January 6, 2011 with over 1,000 apps, the Mac App Store brought one-click purchase and install to the Mac, logging a million downloads in a day.