Senior iOS Developer (Swift + Objective-C) - 13” iPad Kiosk Checkout Redesign

We are implementing a redesigned 13” iPad kiosk checkout flow (Pages 1–6) inside an existing Swift + Objective-C PoS application. This is a state-driven, timer-governed transactional flow requiring strict cart validity enforcement and payment lifecycle correctness. This is not a simple UI reskin. The flow includes: • Event & performance selection • Reserved seating with cart timer supremacy • Tier-gated eligibility logic • Add-ons & promotion recalculation • Checkout configuration with loyalty-based prefill • Payment authorization via external device • Strict separation of recoverable vs terminal failures • Hard session reset with privacy guarantees Deliverables • Implement redesigned UIKit-based UI for Pages 1–6 • Enforce navigation gating and state correctness • Preserve cart timer authority across all pages • Integrate with existing services (events, cart/holds, pricing, loyalty, payment callbacks) • Prevent duplicate actions (idempotent payment initiation, tap debouncing) • Ensure no duplicate order creation and safe void handling in edge cases • Deliver TestFlight build at end of sprint The existing app is UIKit-based with established service layers for events, cart holds, pricing, loyalty, and payment device callbacks. We are looking for a senior iOS engineer comfortable with: • Swift + Objective-C interop • UIKit on iPad • Transactional or POS-style flows • State-driven navigation and timer-based validity • Payment integration handling and edge cases How We Like to Work • 1–2 day paid discovery phase first (implementation plan + risks) • Followed by a structured 2-week milestone sprint • Daily commits and brief progress updates • Clear ownership and pragmatic decision-making (no unnecessary refactors) • Direct communication and fast feedback cycles We expect clean, maintainable code and thoughtful handling of edge cases (race conditions, rapid taps, background/foreground behavior). Please include in your proposal: 1. Confirmation you can start within 48 hours 2. Your estimated fixed price for discovery 3. A brief explanation of how you would structure a cart-timer-driven checkout flow with terminal vs recoverable payment states We value correctness, reliability, and clean execution. To confirm you’ve reviewed this posting carefully, please include the phrase “TimerSupremacy” in your proposal. Apply tot his job Apply To this Job