Expo Push Notifications: The Complete Implementation Guide (SDK 52+)

Expo push notifications are alerts sent from a server to a user's phone, even when the app isn't open. To set them up, install the expo-notifications library, ask the user for permission, and get a unique push token for their device. Your server sends a message to Expo's push service with that token, and Expo delivers it through Apple or Google. Push notifications only work on real phones, not simulators. Local notifications are different — they're scheduled by the app itself for things like reminders. You can also route Expo push through services like Courier to add email, SMS, and Slack fallbacks.

Best Email API Providers for Developers in 2026: SendGrid vs Postmark vs Mailgun vs SES vs Resend

Your email provider sticks with you longer than most technical decisions. Courier handles notification infrastructure for thousands of teams, so we went deep on the six email providers that show up most: SendGrid, Postmark, Mailgun, Amazon SES, Resend, and SMTP. This guide covers real API primitives, actual code from each provider's docs, Courier integration examples with provider overrides, and an honest read on where each developer experience holds up and where it breaks down. We also asked Claude to review every API and tell us which one it would wire up first. The answer surprised us.

A Resilient Notification Strategy for Regulated Industries

Notification compliance isn't a legal checklist—it's an infrastructure problem. In 2026, Reg E deadlines, HIPAA content rules, and TCPA consent requirements dictate your system architecture. This guide breaks down the engineering constraints of regulated notifications for fintech, healthcare, and insurance. Learn why hard-coded deadlines fail, how "alert without disclosing" works in practice, and why the smart escalation pattern (Push → SMS → Email) is the only way to satisfy both user urgency and regulatory documentation. Build systems that absorb complexity, not application code that breaks every time a state law changes.