Case 04 / 2026

MegaWahl — E-commerce data platform

MegaWahl (megawahl.de) · E-commerce · Retail Platform

Sector
E-commerce · Retail
Scope
  • Data pipeline (ETL)
  • Shopify integration
  • AI categorisation
  • SEO automation
Stack
  • Python · Polars
  • Shopify Bulk GraphQL
  • Batch APIs (LLM)
  • Local vision model
Timeframe
2026 · since 05/2025
Live
megawahl.de (opens external site)
Home page of the MegaWahl online shop (megawahl.de) — hero „Alles für Büro & Gewerbe“, over 17,000 products
Exhibit A — Home

Starting point

A growing Shopify shop stocking around twenty suppliers — each with its own catalogue format (CSV, XLSX, PDF), its own encoding, its own logic. Doing it by hand does not scale: creating products, translating, categorising, adding SEO — thousands of times, consistently, with no lost SKU numbers.

Brief

A data platform that automatically turns supplier catalogues into clean Shopify imports — project-based, as a standalone Python system alongside the shop.

Build

Eleven supplier processors (a shared BaseProcessor architecture, Polars) normalise the raw data. A transactional SKU manager assigns numbers with rollback (reserve → validate → commit/cancel) — no number is ever lost. An asynchronous translation pipeline (Polish→German) preserves HTML structure and protects non-translatables like SKUs and brand names. The core: an AI product categorisation across the live catalogue — embedding retrieval (BGE-M3) proposes candidates, a local vision model with constrained decoding decides (token masking: the model physically cannot invent a category outside the Google taxonomy), and every decision passes through a human review before it is written back to the shop.

Mobile home page of the MegaWahl online shop with product selection
Exhibit B — Mobile

Outcome