Integrate WisePos Payment Terminal

COPE is looking for a mid-level mobile engineer to integrate a Stripe BBPOS WisePad 3 payment terminal into our existing Flutter application. The backend payment system, Stripe integration and broader commerce infrastructure are already in place. Your responsibility is the end-to-end mobile and reader experience: connecting the WisePad 3 over Bluetooth, implementing card-present payments, supporting offline collection and integrating the resulting flows with our existing APIs. This is a focused delivery project running until the integration is production-ready. ## What you’ll work on * Integrate Stripe Terminal’s native iOS and Android SDKs into our Flutter app * Build and maintain the Flutter-to-native boundary in Swift and Kotlin * Discover, connect and reconnect WisePad 3 readers over Bluetooth * Implement online and offline card-present payment flows * Integrate payment state and synchronisation with our existing backend * Handle app restarts, connectivity loss, reader disconnections and interrupted payments * Prevent duplicate payment attempts through clear state management and idempotent flows * Surface pending, completed, declined and failed payments clearly in the UI * Add useful logs, diagnostics and production telemetry * Test the integration on physical iOS and Android devices * Document the architecture and operational failure modes ## What success looks like * Users can connect and use a WisePad 3 without technical assistance * Payments remain understandable when connectivity is unreliable * Offline payments are safely forwarded when the device reconnects * Pending payments remain visible until their final status is known * Retries, repeated taps and app restarts do not create duplicate payments * The team can diagnose reader and payment issues from production telemetry * The integration remains maintainable as Stripe updates its native SDKs ## What we’re looking for You should have: * Professional experience shipping Flutter applications * Experience working with both Swift and Kotlin * Experience integrating native SDKs into Flutter * A strong understanding of asynchronous state and mobile lifecycle behaviour * Experience with payments, checkout or other transactional systems * Experience with Bluetooth hardware or similar device integrations * An understanding of idempotency, retries and eventual consistency * Confidence testing against real hardware * Clear communication and pragmatic technical judgement Experience with Stripe Terminal, Flutter plugin development, offline-first applications, payment reconciliation or point-of-sale systems is particularly relevant. ## How we work We value engineers who model difficult states explicitly, design recovery paths before shipping and leave systems easier to understand. The backend is not part of the greenfield scope. You will work with our existing engineers and APIs, but you should be comfortable owning the mobile implementation from technical design through production release.