Name: Duxly
Address: NL
Rating: 5.0

API Integration Checklist for E-commerce Platforms

Getting your e-commerce stack to work as a unified whole — rather than a collection of siloed tools — comes down to one thing: solid API integration. Whether you’re connecting Shopify to an ERP, syncing a PIM system with your webshop, or wiring up a logistics provider, the fundamentals stay the same. Miss a step, and you’ll be chasing phantom stock issues at 2 a.m.

This checklist walks you through every phase: from assessing what you need, to keeping integrations healthy months after launch.

Phase 1: Pre-Integration Assessment

Before writing a single line of code, take stock of your current environment. A rushed start almost always means rework later.

Questions to answer upfront:

Which systems need to talk to each other, and in which direction?
What is the source of truth for each data type (products, stock, orders, customers)?
How often does data need to be exchanged — real-time, near-real-time, or batch?
What are the peak load expectations (Black Friday, campaign launches)?
Are there compliance requirements (GDPR, PCI-DSS) that affect data flows?

Draw a simple diagram with every system, data flow, and ownership boundary. This artefact prevents misunderstandings between developers, operations, and stakeholders.

Real example: When connecting Shopify to a legacy ERP (SAP Business One, Microsoft Dynamics), the first decision is: does Shopify own product data, or does the ERP? Getting this wrong means duplicate-write conflicts within days.

Phase 2: Integration Patterns — Choose the Right Architecture

Not all integrations should work the same way. Choosing the wrong pattern creates bottlenecks or unnecessary complexity.

Pattern	How it works	Best for
Synchronous (REST/GraphQL)	Request → wait → response	Real-time price lookups, cart validation, payment status
Asynchronous (queue-based)	Send message → process later	Order creation, stock updates, fulfilment events
Event-driven (webhooks)	System pushes events on change	Order status updates, inventory alerts, shipment tracking
Batch processing	Bulk data transfers on a schedule	Nightly catalogue syncs, invoice exports, reporting

For most e-commerce setups, a hybrid approach works best: synchronous calls for customer-facing operations where latency matters, and async/event-driven flows for back-office processes.

Real example: A PIM system (like Akeneo or Contentful) syncing product data to a webshop rarely needs real-time sync. A nightly or hourly batch keeps catalogues current without hammering APIs. Order statuses, however, should trigger webhook events immediately so customers see accurate shipping information.

Phase 3: Security Requirements

Security in API integrations is non-negotiable — especially when order data, customer PII, and payment flows are involved.

Authentication & Authorisation

Method	When to use	Key consideration
API Keys	Machine-to-machine, low sensitivity	Rotate regularly; never commit to source control
OAuth 2.0	User-delegated access	Use short-lived access tokens + refresh tokens
JWT	Stateless service auth	Validate signature and expiry on every request
mTLS	High-security server-to-server	Strong guarantees, but higher operational complexity

Rate Limiting

Every external API enforces rate limits. Ignoring them leads to 429 Too Many Requests errors that silently break your integrations. Always:

Check the rate limit headers (X-RateLimit-Remaining, Retry-After)
Implement exponential backoff with jitter on retries
Use a queue or token-bucket mechanism to throttle your own outbound calls

API Versioning

APIs change. Providers deprecate endpoints, rename fields, and change response shapes. Protect yourself:

Always pin to a specific API version (/api/v2/orders, not /api/latest/orders)
Subscribe to provider changelogs and deprecation notices
Test against new API versions in a staging environment before migrating

Webhook Validation

Webhooks arrive from the outside world — verify they actually come from who they claim to be:

Validate the HMAC signature on every incoming webhook (e.g. Shopify uses X-Shopify-Hmac-Sha256)
Reject invalid or missing signatures with 401
Use short processing windows to defend against replay attacks

Phase 4: Error Handling & Retry Strategies

Integrations fail. Networks blip, APIs go down for maintenance, payloads get malformed. Plan for this from day one.

Retry strategy — the basics:

Idempotency keys — ensure retrying an operation (e.g. creating an order) does not create duplicates. Most modern APIs support this natively.
Exponential backoff — retry after 1s, then 2s, 4s, 8s — with randomised jitter to avoid thundering herd problems.
Dead-letter queues (DLQ) — messages that fail after N retries should land in a DLQ for manual inspection.
Circuit breakers — if a downstream service is consistently failing, stop hammering it. Open the circuit, fail fast, retry after cooldown.

Error type	Recommended handling
`4xx` (client error)	Log and alert — likely a data or config problem, don’t retry blindly
`429` (rate limit)	Retry after the `Retry-After` value
`5xx` (server error)	Retry with backoff; escalate if persistent
Network timeout	Retry with backoff; check idempotency before retrying

Phase 5: Performance Optimisation

A slow integration is almost as bad as a broken one. These optimisations matter at scale.

Caching: Cache responses that don’t change often — product catalogues, shipping zone lookups, exchange rates. Use TTLs that match the update frequency of the source data.
Batch operations: Use bulk API endpoints where available. Sending 500 product updates in one request instead of 500 individual calls reduces both latency and rate-limit exposure.
Pagination: Always handle paginated responses correctly — failing to page through all results is a common source of incomplete syncs.
Compression: Enable gzip/brotli for large payloads. A full product catalogue can be 60–80% smaller compressed.

Phase 6: Monitoring & Observability

You cannot manage what you cannot measure. Once an integration is live, you need visibility.

Three pillars of observability:

Logs — structured logs (JSON) for every API call: timestamp, endpoint, status code, response time. Store centrally (Datadog, Grafana Loki, CloudWatch).
Metrics — track success rate, error rate, p95/p99 latency, queue depth, sync lag. Expose to a dashboard your team actually looks at.
Alerts — define thresholds and alert before customers notice. Common alerts: error rate > 1%, response time > 2s, DLQ depth > 0, webhook failures.

Metric	Target	Alert threshold
API success rate	> 99.5%	< 99%
Sync lag (orders)	< 60 seconds	> 5 minutes
Webhook delivery	> 99%	< 95%
p95 response time	< 800ms	> 2000ms

Phase 7: Documentation Requirements

Good documentation is what separates a maintainable integration from one that only the original developer can touch.

Every integration should have:

Architecture diagram — systems, data flows, ownership
Data mapping table — how fields map between systems (e.g. Shopify product.variants[].sku → ERP itemCode)
Error catalogue — known codes and how to handle them
Runbook — step-by-step guide for common ops tasks (re-syncing failed orders, rotating keys, handling deprecated endpoints)
Changelog — every change, dated and described

Phase 8: Vendor Lock-in Considerations

Tight coupling to a single vendor’s API is a strategic risk. APIs get retired, pricing models change, or vendors stop fitting your needs.

Mitigation strategies:

Abstraction layers — build an internal interface that your business logic calls; swap the underlying API adapter without touching core code
Avoid proprietary formats — transform vendor-specific data to your own canonical schema early in the pipeline
Export rights — before signing contracts, verify you can export all data in portable formats
Multi-vendor fallback — for critical functions (payments, shipping), maintain at least two provider integrations

Quick-Reference Checklist

Phase	Checklist item	Done?
Assessment	Integration landscape documented	☐
Assessment	Source of truth defined per data type	☐
Architecture	Integration pattern selected	☐
Security	Authentication + rate limiting in place	☐
Security	Webhook signatures validated	☐
Security	API version pinned	☐
Error handling	Idempotency keys + DLQ configured	☐
Performance	Caching + batch operations implemented	☐
Monitoring	Logging, dashboards, alerts configured	☐
Documentation	Architecture diagram + runbook written	☐
Vendor risk	Abstraction layer in place	☐

Ready to Integrate?

A well-executed API integration cuts manual work by hours per week, reduces errors that cost you orders, and gives your team real-time data for better decisions.

At Duxly, we specialise in e-commerce integrations — Shopify, Magento, WooCommerce, ERP systems, PIM platforms, logistics providers, and more. We’ve seen what goes wrong and know how to build integrations that hold up under real load.

Want an experienced partner for your integration project? Get in touch with Duxly — we’ll assess your setup and recommend the right approach.

API Integration Checklist for E-commerce Platforms