Summary: Data typed twice means double the cost and errors. API integration creates a single source of truth and syncs automatically between applications.
Signs You Need Integration
- Staff copy data between apps every day.
- Stock, prices, or statuses differ across systems.
- Reports must be assembled manually from many sources.
- Customers receive inconsistent information.
4 Integration Patterns
| Pattern | How it works | Best for |
|---|---|---|
| Webhook / event | System A tells B when something happens | Real-time, orders, payments |
| Scheduled polling | Pull data periodically | Systems without webhooks |
| Batch (file/SFTP) | Scheduled export-import | Legacy ERP |
| Middleware / iPaaS | A central layer (n8n) | Many systems, frequent change |
If there is no API at all, see RPA.
Best Practices
- Define the source of truth for each entity (customer, product, stock).
- Idempotency: reprocessing the same message does not duplicate data.
- Retry with backoff and a dead-letter queue.
- Documented data mapping (field A ↔ field B).
- Secure authentication: OAuth2/API keys in a secret manager, not in code.
- Rate limits: respect third-party API limits.
- Observability: logs, dashboards, and failure alerts.
- API versioning: be ready for vendor changes.
Common Integrations
- Website/marketplace → ERP → accounting (order to invoice).
- Lead form → CRM → WhatsApp/email follow-up.
- Payment gateway → order system → shipping.
- HRIS → payroll → accounting.
Risks
Third-party schema changes, dirty source data, and two-way conflicts (two systems changing the same data). Design conflict-resolution rules from the start.
FAQ
How long does an integration take to build?
It depends on API documentation quality and the number of entities; a simple flow can be quick, many systems need a discovery phase.
Build code or use n8n?
n8n is fast for common flows; custom code for performance, complex logic, or very high volume.
Next steps
List of systems you want to connect? Send it to us; we will map the flow and approach.