I’m rolling out a product that runs simultaneously on the web, iOS and Android, and I need a clean, unified way to handle user entry and keep everyone informed in real time. Authentication scope • Support OAuth flows (Google, Apple, etc.) • Maintain JWT-based sessions for our own username/password route • Offer social-media sign-ins side-by-side, all funnelling into a single user table Notification scope • Email messages for transactional events • Push alerts on the mobile apps • SMS for time-sensitive updates Deliverables 1. Reusable modules or SDK integrations for each platform 2. Secure backend endpoints (or rules) that issue and verify tokens 3. Trigger logic that selects the correct channel—email, push or SMS—based on user settings 4. Clear setup notes so my in-house team can extend or audit the work Acceptance criteria • Working demo on all three platforms with test users • Tokens validate and refresh correctly across methods • Messages arrive within expected timeframes and are logged for troubleshooting If you’ve already connected services such as Firebase Auth, AWS Cognito, Auth0, OneSignal, Twilio or similar, you’ll feel right at home here, but I’m open to any robust stack as long as the finished code is documented and portable.