Custom Shopify App for Swiss Post & FedEx

The objective of this project is to develop a custom public Shopify application that integrates our store natively with the official Swiss Post (La Poste Suisse) and FedEx APIs.

The app must allow our team to manage the entire fulfillment workflow directly from the Shopify Admin panel using Shopify App Bridge and Polaris UI, without ever logging into the external Swiss Post web portal.

Required Features:
-Partial Fulfillment UI: Select specific items and quantities for each package directly on the Shopify order page.
-Automated Customs & PDDP: Automate CN22/CN23 forms based on value. Support complex country-specific Postal DDP (PDDP) rules and EORI inputs (for USA, FR, DE, AT).
-Smart Tracking Write-back: Automatically update tracking inside Shopify and dynamically map the destination's national postal carrier (e.g., USPS, Royal Mail, La Poste). No tracking for Economy shipments.
-Workflow Automation: Embed a pre-uploaded digital signature on customs PDFs, log actions on the native Shopify Order Timeline, and support label cancellation (which must delete the Shopify fulfillment to reset the order state).
-App Settings: Manage multiple sender address profiles, fallback currencies for unsupported store currencies, and FedEx notification emails.

Deliverables:
A fully functional Shopify app deployed on Shopify Appstore and clean, documented source code.

A highly detailed Scope of Work (SoW) document and Loom videos showing our current manual workflow are ready to be shared with the selected freelancer. Please bid with your estimated timeline and budget.