Same-day restock alerts across 6 sales channels: the architecture

A brand selling across Shopify, Amazon, TikTok Shop, and three wholesale accounts had a recurring problem: they'd find out a bestseller was out of stock only after it had already been overselling on 2-3 channels for days. By the time someone noticed, they were manually apologizing to customers and issuing refunds.

The core issue: no single view of "true" stock

Each channel tracked inventory independently, synced on its own schedule (some hourly, some daily), which meant "available stock" was never actually accurate anywhere. Oversells were discovered reactively — usually by an angry customer, not by the ops team.

The architecture

We built a central inventory ledger that every channel writes to and reads from in near real-time, rather than each channel keeping its own independent count. Every sale, from any channel, decrements the same central number immediately via webhook — no more waiting for a batch sync to catch up.

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The key shift: stop treating each channel's inventory as its own source of truth. One central ledger, pushed out to channels, beats six independent counts trying to reconcile with each other.

Threshold-based alerts, not just zero-stock alerts

Waiting until stock hits zero is too late — by then you've likely already oversold on a slower-syncing channel. We set tiered thresholds (20 units, 10 units, 5 units) that trigger increasingly urgent Slack alerts to the ops and purchasing teams, giving them lead time to reorder or pull listings before a stockout actually happens.

Automatic listing pause on critical items

For the brand's genuine bestsellers, we added a rule: if stock drops below a 3-unit safety buffer, the workflow automatically pauses the listing on the slowest-syncing channels first, protecting against oversells while the faster channels (which sync in real time anyway) keep selling safely.

The results

Oversells dropped by 94% in the first two months
Purchasing team gets restock alerts 5-7 days earlier than before
Customer refunds due to unfulfillable orders dropped to near zero

If you're selling across multiple channels and still finding out about stockouts after the fact, this is exactly the kind of system worth building. Get in touch to talk through your setup.