Push Notifications APNs

Apple Push Notification service (APNs) is Apple's production infrastructure for sending remote push notifications to iOS, iPadOS, tvOS, and macOS apps. Unlike in-app messaging, APNs delivers notifications even when the app is closed or backgrounded, enabling critical alerts, time-sensitive messages, and engagement campaigns. APNs uses either certificate-based or token-based authentication and guarantees high reliability and low latency at scale. Push notifications are a primary engagement and retention driver for mobile apps, particularly on iOS where users expect timely, relevant alerts. Mastering APNs design—batching, prioritization, threading, rich media—separates high-quality apps from noisy ones. Demand is strong in fintech, social, and productivity apps; specialists command 15–25% higher salaries than general mobile developers.