Digital B2B transformation with a modular architecture

As an internationally active specialist, Paul Wiegand GmbH has been supplying cities and municipalities for 30 years with the technical components that keep their utility vehicles running, from the sweeper module to snow plough hydraulics. Customers across Europe source specialist spare parts here, by catalog, phone or increasingly through digital channels. To meet the growing demand for digital services, the company decided on a far-reaching IT modernization.

At the heart of the challenge was an in-house ERP system that had been in use since 2002. The solution had grown over many years and was maintained with deep expertise, but only a handful of people in the company could support and adapt it comprehensively. This created dependencies on a few individuals and, with them, risks for the future. At the same time, many analog processes dominated, because the system could no longer reliably represent core requirements of modern digital processes. The pricing logic was especially problematic, with around 800 different calculation rules that made a high-performance digital price determination difficult. The ERP system was prepared neither for this complexity nor for the demands of modern interfaces.

In addition, different ERP instances existed for various countries and customer groups, which made a unified data structure and cross-channel automation practically impossible. The central task was therefore to develop a modern, modular IT architecture that enabled both centralized data management and flexible adaptation to different market requirements, while remaining scalable and future-proof.

The project started with a consulting mandate. The goal was to replan the technology architecture step by step and to untangle as many dependencies as possible. The result was a modular solution with Nekom as middleware and BigCommerce as a lightweight commerce system, deliberately chosen to keep complexity out of the shop.

Nekom forms the backbone of the system architecture and, as the central middleware, handles the orchestration of product data, customer master data, order processes and web shop documents. The deliberately chosen architecture design made it possible to unlock remarkable synergies between shop and middleware in several areas and to implement core functions especially efficiently, for example a multi-tenant structure with several users per company account or the central management of technical documents such as PDF invoices. By bundling these processes in the middleware, the shop deliberately stays lean and low-maintenance, without extensive custom development.

Beyond that, further features were realized with Nekom and BigCommerce:

• Custom shipping cost rules: Per customer, shipping methods such as DHL Express can be discounted or activated automatically, depending on the order value. The technical limitations were circumvented by manually creating all variants and controlling them via Nekom logic.

• Cart reflection in the list view: Customers see directly which products they have already added to the cart, including the quantity displayed. This function was added through a purpose-built interface.

• Stock logic at zero inventory: Products can generally be ordered even when they are out of stock according to system inventory. The actual stock status is transmitted via a custom field and displayed contextually in the shop ("available on request").

• Registration: New customers first go through an approval in Nekom before they gain access to the shop. Only after approval is the user data synced back. When a registration request is submitted, an email is automatically triggered to shop management.

• B2B features: Quick order lists, individual price calculations including tiered pricing, EDI and OCI connection, location management and much more.

To be able to respond with maximum flexibility to customer-specific requirements in the checkout, Shopmacher additionally built a custom-developed and hosted checkout solution. Among other things, this architecture decision enables extended address processing as well as individual adjustments, tailored precisely to the customer's business processes, and integrates seamlessly into the overall system with BigCommerce.

Paul Wiegand establishes an internationally scalable e-commerce setup together with Shopmacher

Shopmacher also solved the challenge of handling many customer-specific prices. Here a separate API was developed that accesses the ERP system directly. The pricing logic is orchestrated through the Amazon service IDABS, including intelligent caching to reduce system load.

The project started in mid-2024. A year later, 3 shops are already live: Spain as an MVP, Hydracraft as an own brand and the main shop Paul Wiegand.de in seven languages. Further subshops for France and the Netherlands are set to follow by 2025. Thanks to the modularity, it was possible to address specific market requirements, such as different ERP backends, differing shipping logic or country-specific price tiers. The use of translation tools enabled flexible content maintenance.

With the new e-commerce architecture, Paul Wiegand has a scalable infrastructure that can be rolled out internationally. The online presence has been significantly strengthened and customer service inquiries have been reduced. Thanks to real-time price determination, the complex pricing logic is preserved without slowing down the shop. And even less technically inclined users on the customer side find their way around intuitively.

"Shopmacher didn't just build us a new shop, they helped us rethink our business model on a technical level," praises Sebastian Ruhl, Head of Sales & Marketing at Paul Wiegand. "That combination of professional expertise and creative drive was a real game changer for us."