Vansiels

International commerce has tightly coupled conversion risks: pricing consistency, cart state, payment authority, fulfillment, tracking, and mobile UX.

• Multi-market price handling across product, cart, subtotal, and checkout.
• Resilient cart hydration with sanitized display-price snapshots and catalog reconciliation.
• Backend-authoritative payment confirmation using provider webhooks.
• Separate shipping pricing from tracking provider responsibilities.
• Automated order-state progression from packing to delivered.

A real cart regression showed correct pricing on product pages while restored carts lost price data after hydration and a fallback catalog response.

The fix required tracing UI → state → API → fallback data, not patching the visible symptom.

The platform also required cleanup of stale payment integrations and mobile commerce review where technically responsive UI was not enough.

Commerce workflow design, checkout behavior, payment integration, fulfillment state, tracking, cart/pricing diagnostics, mobile UX review, deployment cleanup, and end-to-end testing.