Integrations & API Development

Most day-to-day e-commerce problems do not happen in the store but between systems: stock levels are wrong, orders arrive twice in the ERP, the wholesaler sends a CSV nobody imports cleanly, and shipping labels are created by hand. I build the integrations that close these gaps – with PHP and Symfony, resilient to errors and with logs you can actually read.

I have built and maintained integrations for catalogues with millions of products, marketplace connections and inventory systems. The difference to a quick script: repeatability, error handling, monitoring and documentation your team understands.

Typical tasks

Connect the store to an ERP or inventory system

Synchronise products, prices, stock and orders between Shopware and your ERP (e.g. JTL, weclapp, Xentral, SAP Business One, Microsoft Dynamics) or a custom inventory system – in both directions, with clear rules about which system leads.

Import wholesaler and supplier catalogues

CSV, XML, BMEcat, Excel or a supplier API: import product data regularly, clean and map it, calculate prices and update stock – for very large catalogues and several suppliers in parallel.

Logistics and fulfilment

Automate shipping labels, tracking, returns and stock levels with DHL, DPD, GLS, UPS or a fulfilment provider – no more copying between portals.

Marketplaces: Amazon, eBay, Kaufland, Otto

Maintain listings, fetch orders, reconcile stock and push invoices back – via the official APIs or a middleware provider, whichever makes economic sense.

Payment and invoicing systems

Connect payment providers, accounting (e.g. DATEV export, lexoffice, sevDesk) and invoicing – including reconciliation of incoming payments.

PIM and DAM systems

Maintain product information and media centrally and push them to store, marketplaces and catalogues – or a lightweight PIM as a custom application when a standard system is too big.

Stabilise an existing integration

A connection runs but fails regularly, loses records or takes hours. I analyse it, add error handling and resumption, and make it observable.

Provide your own API for partners or apps

A documented REST API (e.g. with API Platform) through which partners, field sales or a mobile app access orders, products or customer data – with authentication, permissions and versioning.

How I work

1. Clarify data flows: Which data, in which direction, how often, which system leads, what happens on conflicts?
2. Build the integration: As a standalone service or as a Shopware plugin – wherever it belongs long term. Idempotent, with queues and retries on failure.
3. Monitor and hand over: Logs, notifications on failures, documentation and handover to your team or hosting provider.