Middleware

Middleware is a software layer that sits between several applications and mediates the data exchange between them. Instead of connecting every system directly to every other one, all systems talk only to the middleware.

Explanation

The term is broad. It covers messaging systems that buffer and distribute data, integration servers in large companies and cloud platforms such as iPaaS. What they all have in common: the middleware accepts data from one system, converts it, forwards it and logs what happened.

This pays off mainly when many systems are involved. With ten systems that all exchange data with each other, a web of individual connections quickly becomes unmanageable. Middleware brings order. But it is itself a system that has to be operated, maintained, secured and paid for. If it fails, all connections stop at once. For small and medium-sized companies with two to four systems, middleware is therefore often more effort than benefit.

Example from everyday integration work

A retailer has a shop, a marketplace account, an ERP, a shipping tool and an accounting system. Middleware collects orders from shop and marketplace, distributes them to the ERP and shipping, and hands invoices to accounting. A smaller business with just a shop and accounting does not need this additional layer. A direct connection is enough for it.

How it differs from related terms

• Direct integration: connects two systems without a layer in between. Fewer moving parts, lower cost, but one connection per pair of systems.
• iPaaS: middleware as a cloud service with building blocks and a subscription.
• API: the door through which middleware talks to the individual systems.
• Vendor lock-in: a risk if the middleware belongs to a provider and the workflows cannot be taken along.

Relevance to our services

We deliberately do not build middleware or a hub, but direct integrations from system A to system B. With several systems, we plan the connections so that one system leads for each data object. When which approach fits is explained in the guide Connector or custom integration? For projects with shop and ERP, see shop-ERP integration.

Updated: 10/20/2026