Migrating a B2B/B2C shop from ASP.NET to WooCommerce, then integrating it with the ERP

This is the project I mention most often when people ask what I can do beyond a brochure website. It combines the three things that make an e-commerce takeover difficult: a large catalogue, a starting technology that nobody wants to maintain any more, and a management system to connect behind it.

The starting point

The client ran an online shop built on a proprietary ASP.NET platform. The model worked commercially, but it locked them in: every change went through a single vendor, the skills were becoming scarce and the cost of ownership was rising. The decision was to move to an open, documented foundation — WordPress / WooCommerce — without losing any of the catalogue or the search rankings already earned.

Phase one: the migration

44,919 products were carried over from the old system. A catalogue of this size cannot be migrated by hand: it is processed with scripts, with consistency checks at every pass, and acceptance testing based on representative samples rather than three product pages picked at random.

Beyond migrating the data, this phase included:

• designing a complete design system, so that the shop no longer depends on a bought theme;
• a header designed for two audiences, B2B and B2C, who have neither the same prices nor the same journeys;
• instant AJAX search and a mega-menu, essential once a catalogue goes beyond a few thousand products;
• recovering the existing editorial pages, often forgotten in migrations even though they bring in traffic;
• server-side anti-crawler protection.

The incident resolved along the way

That last point was not theoretical. In production, the server climbed to 256% CPU load with no matching spike in human traffic. The diagnosis identified an AI service’s crawler working through the catalogue without any limit. The problem was solved at server level, not in the website: exactly the kind of issue that a provider who does not touch the infrastructure can neither see nor fix.

Phase two: connecting the shop to the business management system

A shop like this does not live on its own: products, prices, stock and orders have to flow between the website and the client’s ERP — here Microsoft Dynamics 365 Business Central, in its SaaS version, through an exchange middleware.

This part is less about web development than about systems integration: OAuth 2 authentication against the vendor’s identity directory, a sandbox environment, permissions management, and above all coordination with the ERP integrators, who work neither at the same pace nor with the same vocabulary.

What this project really demands

Three skills that rarely go together: handling a catalogue in bulk without degrading it, running a server in production, and talking with an ERP vendor. It is the profile agencies and IT consultancies look for when they subcontract an e-commerce project: someone who takes on the whole subject rather than just the visible part.

See also: WooCommerce expertise · ERP integration · For agencies and IT consultancies.