https://www.swiftdifferently.com/blog SwiftDifferently is an iOS engineering blog created with ♥️ and passion by Omar Elsayed. en-us omar@swiftdifferently.com (Omar Elsayed) omar@swiftdifferently.com (Omar Elsayed) Sun, 30 Aug 2026 00:00:00 GMT https://www.swiftdifferently.com/blog/swift/drawin-notification https://www.swiftdifferently.com/blog/swift/drawin-notification How do you tell a DNS proxy extension that its 250k-domain blocklist changed? Not with `NotificationCenter` — that stops at the process boundary. Darwin notifications, `notifyd`, C callbacks, and why "system-wide" cuts both ways. Sun, 30 Aug 2026 00:00:00 GMT omar@swiftdifferently.com (Omar Elsayed) macOSswift