Workflow automation on n8n (self-hosted), no LLM agent — deterministic process orchestration that replaced four disconnected order, inventory, fulfillment, and returns processes for a DTC home-goods brand selling across Shopify and three marketplaces.

The client sells through Shopify and three marketplaces simultaneously. Before the project, each channel lived in isolation: operators manually copied Etsy and Walmart orders into Shopify, inventory was reconciled in Google Sheets once a day, and returns were handled through email chains between support, the warehouse, and accounting. As volume grew past 600+ orders/day, the process started breaking down — selling stock that was no longer available, duplicate orders, and refund delays of 5–7 days.

The team had looked at Zapier, but the cost at that trigger volume (600+ orders × 4–6 steps each) blew past budget, and the conditional logic needed (different rules per marketplace) required custom branches that Zapier prices especially steeply.