Shopify Third-Party API Backend Integration | Remote

Get a production-ready third-party API integration on your Shopify store backend—delivered remotely for merchants who need stable sync, not experimental apps. We design, build, and harden the connection so inventory, orders, customers, and fulfilment stay consistent across the tools you already run.

What You'll Get

• Scoped API architecture - Clear map of endpoints, auth method, rate limits, and data ownership before a single line of code ships.
• Shopify Admin / Storefront API wiring - Custom app or private integration paths for products, inventory, orders, fulfilments, and metafields.
• Webhook & queue handling - Reliable event intake with retries, idempotency keys, and dead-letter paths so spikes do not drop updates.
• Auth that survives rotation - OAuth, API keys, or JWT handled with secure secret storage and documented renewal steps.
• Error surfaces you can act on - Structured logs, admin-facing failure notes, and alerts when third-party downtime or schema drift hits.
• Handoff docs & optional monitoring - Runbook for your team plus a light health check window if you want ongoing eyes on the pipeline.

Serving Remote & surrounds

This service is built for remote delivery worldwide: screen-share discovery, secure credential exchange, staging first, then controlled production cutover. We focus on merchants whose peak risk is seasonal—Black Friday inventory thrash, subscription renewal waves, and multi-warehouse handoffs—rather than one-off theme tweaks.

• DTC brands syncing Shopify to ERP or WMS during high-volume catalogue drops
• Subscription and membership merchants needing billing or CRM APIs that must not double-charge
• Fully remote delivery; on-site pairing only where practical for your region and security policy

How We Work

1. Step 1: Reach Out - You describe the systems to connect (ERP, CRM, shipping, payments, custom SaaS), current pain, and must-not-break flows. We listen first and ask for sandbox access where possible.
2. Step 2: Tailored Plan - Fixed-scope quote covering endpoints, auth, webhook strategy, test plan, and cutover window—no open-ended hourly fog.
3. Step 3: We Deliver - Build and test in staging, validate edge cases (partial fulfilments, refunds, stockouts), then deploy with rollback notes.
4. Step 4: Confirm & Follow-up - Plain-English handoff, credential checklist, and optional maintenance or a second-phase endpoint if your roadmap needs it.

Common Issues & How to Fix Them

These are patterns we see repeatedly on Shopify backends—not generic API advice. Use the DIY steps to triage; escalate when data is already diverging in production.

Inventory “ghost stock”: Shopify shows available units the warehouse already shipped

Usually a one-way push with no fulfilment webhook ack, or location IDs mapped to the wrong warehouse after a multi-location change.

1. Step 1: In Shopify admin, open a recently shipped SKU and note inventory item ID, location name, and last adjustment timestamp; compare to the WMS/ERP stock row for the same SKU and location code.
2. Step 2: Confirm your integration writes inventory levels to the correct location ID (not the shop-level aggregate) and that fulfilment webhooks update inventory after ship—not only on order create.
3. Step 3: Force a single test adjustment via the Admin API for one SKU at one location, then verify both systems match within one poll/webhook cycle; if they diverge again after the next real shipment, the mapping or ack path is still wrong.

OAuth token death spiral: overnight jobs start failing with 401 after a quiet week

Common when refresh tokens are stored but never rotated on schedule, or when a custom app was reinstalled and old secrets still sit in cron config.

1. Step 1: Check the last successful API call timestamp in your job logs and whether failures cluster after deploy, app reinstall, or password/staff permission changes.
2. Step 2: Re-authorise the custom app in a staging shop first; update client ID/secret and refresh flow so access tokens are renewed before expiry—not only after a 401 storm.
3. Step 3: Run a dry-job that hits a low-risk read endpoint (e.g. shop or product count), confirms 200, and writes a “token healthy” heartbeat; only then re-enable write jobs.

Duplicate customer or order records after “successful” sync

Happens when the integrator keys on email alone, ignores Shopify’s idempotency patterns, or retries POST without a stable external ID after a gateway timeout.

1. Step 1: Pull two sample duplicates and compare created_at, tags/metafields, and any external ID your CRM/ERP stamps back onto the Shopify resource.
2. Step 2: Switch create logic to upsert: look up by stable external_id or Shopify GID first; on network uncertainty, retry with the same idempotency key instead of a blind new POST.
3. Step 3: Replay one known timeout scenario in staging and confirm a single record exists on both sides with matching external references—no second “ghost” row.

When DIY is not enough (urgent, unsafe, recurring, or burning time), book Fixwebnode for direct professional support—no freelancers, bidding, or marketplace noise.

Why Choose Fixwebnode

We deliver the integration ourselves as a direct provider: technical depth on Shopify APIs plus clear explanations for operators who are not full-time developers. Remote-first means faster iteration across time zones without diluting ownership of the build.

• ✓ Backend-first Shopify experience (Admin API, webhooks, custom apps)—not theme-only tweaks
• ✓ Fixed package scopes with staging-before-production discipline
• ✓ Human handoff: runbooks your ops team can actually follow at 2 a.m. during a sale

Tools & Technologies

Shopify Admin API & webhooks, Shopify custom apps, GraphQL and REST where appropriate, OAuth 2.0 / API key patterns, Node.js or Python workers, queue/retry layers, metafields and multipass patterns when needed, Postman/Insomnia for contract tests, structured logging, and secure secret handling for production credentials.

Perfect For

Growing Shopify merchants—especially DTC, subscription, and multi-warehouse brands—who must connect ERPs, CRMs, 3PLs, or niche SaaS tools without fragile Zap-only stacks. Also a fit for small ops teams that want one accountable provider, remote delivery worldwide, and documentation they can hand to support staff after go-live. If your catalogue, orders, or customers already drift between systems, this is the engagement designed to stop the bleed.

Ready to scope endpoints and a safe cutover? Start a conversation via fixwebnode.com.au/contact-support—we will respond with a clear plan, not a bidding thread.