Custom Shopify Shipping App

I need an experienced Shopify app developer to build a tailor made app that plugs seamlessly into my existing store, adds the shipping service integrations I rely on, and respects the performance standards my customers expect. The core of the job is full-stack: you will work with the Shopify API and Liquid on the storefront side, then craft the app’s back end in Node.js (or a comparable stack you are comfortable with) and, ideally, shape a React-based interface that feels native to the Shopify admin.

Here is what success looks like for me:

• The app installs smoothly through the Shopify App OAuth flow, requests only the permissions it truly needs, and leaves no orphaned webhooks or scripts on uninstall.
• It connects to the major shipping services I use, pulls live rates, and writes tracking data back into the order timeline.
• The UI follows Shopify Polaris guidelines so staff can jump in without training.
• Response times stay low even when order volume spikes; your code is clean, modular, and documented so future updates are straightforward.

You will own architecture decisions, advise on best practices, and keep me in the loop with short progress demos. If you have shipped production grade Shopify apps before especially ones that touch external carrier APIs let’s talk details and schedule.