1 The Problem: Data Everywhere, But Not Where You Need It
A typical scenario in mid-sized businesses: The online shop runs on Shopware, inventory management on Xentral, accounting on DATEV, CRM on HubSpot, and marketing automation on Klaviyo. Each system works on its own – but together?
The typical symptoms:
- Orders are manually transferred to the ERP
- Inventory levels don't match between shop and warehouse
- Customer data exists in 5 systems – all different
- Invoices are created via copy & paste
- Nobody has a complete view of the customer
The result: Lost time, errors, frustrated employees, and unhappy customers. The solution? Middleware.
2 What is Middleware?
Middleware is software that mediates between other software systems. It takes data from System A, transforms it if needed, and pushes it to System B – automatically, reliably, and without human intervention.
Middleware in practice:
The advantage: You don't need to connect every system directly to every other. Instead, each system only communicates with the middleware – and it handles the rest.
3 Middleware Options Compared
Four solutions have established themselves for mid-sized businesses, each with their own strengths:
n8n
Open-source workflow automation. Self-hosted or cloud. Maximum flexibility, but also complexity.
Make (formerly Integromat)
Visual automation platform with strong focus on complex scenarios. Good value for money.
Zapier
The market leader with over 5,000 app integrations. Easiest to use, but also most expensive.
Xentral Connect
iPaaS platform for Xentral users. Connects Xentral with shops, marketplaces and other systems.
| Criterion | n8n | Make | Zapier |
|---|---|---|---|
| Entry price | €0 (Self-hosted) | from €10/month | from €20/month |
| GDPR | ✓ (Self-hosted) | ✓ (EU servers) | ⚠️ (US servers) |
| Learning curve | Steep | Moderate | Flat |
| Flexibility | Very high | High | Medium |
| Shopware connector | Community | Official | Official |
4 Typical Integration Scenarios
Which processes can be automated with middleware? Here are the most common use cases:
Shop → ERP: Synchronize Orders
New orders from Shopware are automatically created as orders in Xentral. Including customer data, items, prices, and payment information.
ERP → Shop: Update Inventory
Inventory changes in the warehouse are transferred to the shop in real-time. Never again "Unfortunately out of stock" after the order.
ERP → Accounting: Export Invoices
Created invoices are automatically transferred to DATEV, lexoffice, or sevDesk. No more manual export needed.
Shop → Marketing: Synchronize Customer Data
New customers and orders are transferred to Klaviyo, Mailchimp, or HubSpot. For personalized marketing automation.
Marketplaces → ERP: Multi-Channel Orders
Orders from Amazon, eBay, Otto, and other marketplaces are centrally consolidated in the warehouse management system.
5 The Path to Integration: Step by Step
A successful middleware implementation follows a clear process:
Document Processes
Before you automate, you need to understand what you're automating. Map out current data flows – including all manual steps.
Identify Quick Wins
Start with processes that are easy to automate and immediately save time. Typical: Order sync Shop → ERP.
Choose Tool
Based on your requirements (GDPR, budget, complexity) decide on a middleware solution.
Implement Pilot Project
Implement the first workflow in test mode. Check data quality and fix errors.
Set Up Monitoring
Error notifications, logging, and dashboards are mandatory. You need to know when something isn't working.
Expand Gradually
After successful pilot, add more integrations. Always one workflow at a time, never everything at once.
6 Avoiding Common Mistakes
In middleware projects, we see the same problems again and again:
❌ Automating Everything at Once
Anyone automating 20 processes simultaneously loses track. Start with 1-2 critical workflows and expand gradually.
❌ No Error Handling
What happens when an API is unreachable? Without retry logic and error notifications, data gets lost.
❌ No Monitoring
"It's running" – until it isn't and nobody notices. Without monitoring, you only find problems when customers complain.
❌ Forgetting Documentation
In 6 months, nobody remembers why the workflow was built that way. Document every workflow with purpose, trigger, and actions.
7 Conclusion
Middleware isn't a nice-to-have luxury, but necessary infrastructure for growing e-commerce businesses. The question isn't if, but when and how.
The key points:
- Middleware connects your systems and eliminates manual work
- n8n for GDPR and flexibility, Make for value, Zapier for simplicity
- Start small: One workflow, well tested, with monitoring
- Error handling and documentation aren't optional, they're mandatory