Multichannel E-Commerce & Marketplace Integration Platform

The Problem

The brand sells on six marketplaces and its own website, but stock sits with the supplier, whose dealer site has no ordering API. Prices, stock, orders and invoices were updated by hand on every channel, and a single bad bulk operation could wreck the price or stock of thousands of products.

The Approach

Built the ASP.NET Core 10 API around one `IChannelClient` per channel, so adding a channel means implementing that interface. Built the admin panel and storefront with Next.js 16, the supplier ordering bot with Playwright and the WhatsApp bridge with Baileys as separate services, all running in Docker containers.

Engineering Highlights

• An approval gate with a safe default: unconfigured operation types wait for approval, and scope keys automatically supersede stale requests.
• Stock only flows through approved product mappings; marketplace prices of products missing from the list are never touched.
• A code-level read-only mode: with the dev environment wired to production, marketplace, invoice, refund, WhatsApp and email writes are impossible.
• A supplier ordering bot with duplicate-order prevention, a final check, and a screenshot-backed 'needs manual review' list.
• Channel isolation: one marketplace's failure doesn't stop the others, and only read requests are retried on transient 5xx errors.