Operations · Architecture
Operations
How real UK sellers keep stock consistent across four very different marketplace APIs, without drowning in cron scripts.
Stock sync sounds simple — it isn't. Each marketplace has a different API shape, a different rate limit, and a different failure mode. Amazon uses Feeds API and FBA Inventory API for two different fulfilment channels; eBay uses REST Inventory API for modern listings and Trading API for legacy ones; Temu has a strict 4 req/sec rate limit; TikTok Shop sometimes silently fails if you push updates during their nightly maintenance window (22:00-23:00 GMT). A good multi-channel sync architecture handles all of this invisibly.
Goal of this playbook
By the end of this guide you'll understand exactly how to architect stock sync across 4+ marketplaces so that stock is accurate within 15 minutes on every channel, even during marketplace outages.
You’ll need:
30 min
In MaxInvent, the Product table owns the stock number. Every channel (EbayListing, AmazonListing, TemuGoodsId, TiktokProduct) links back via a centralProductId mapping. Stock is never stored per-channel — it's always computed from the pool minus buffers.
15 min
Amazon SP-API supports two relevant methods: Feeds API (bulk, asynchronous, best for 100+ SKUs per push) and Listings Items API (single-SKU, synchronous, best for low-volume or urgent updates). MaxInvent picks automatically: batched SKU updates use Feeds every 15 min, single-SKU urgent updates on dispatch use Listings Items.
Pitfall
Don't exceed Amazon's 'Feeds' endpoint hourly limit (typically 100 submissions/hour for most sellers). MaxInvent batches aggressively — under 50 SKUs per feed is wasteful.
15 min
eBay is split-brained by listing age. Listings created via modern Seller Hub use the REST Inventory API (/sell/inventory/v1/). Legacy listings (created years ago via Turbo Lister, Linnworks etc.) use the Trading API (/ws/api.dll with GetMyeBaySelling). MaxInvent detects which type each listing is and uses the correct API — other platforms often only support REST and fail silently on legacy listings.
10 min
Temu enforces roughly 4 req/sec per seller. With a 1,000-SKU catalogue, that's 4 minutes minimum per full sync cycle. MaxInvent sets Temu cadence to 30 min (safe headroom) and pushes immediately on dispatch as a backstop.
10 min
TikTok Shop's API is straightforward but has a quirk — updates during the maintenance window (22:00-23:00 GMT on most days) can silently fail without returning errors. MaxInvent schedules TikTok syncs outside this window automatically.
Design-level — built into the platform
Every sync job must be idempotent (running it twice produces the same result). Every job must checkpoint progress (if it crashes at SKU 500 of 1000, the next run resumes at 501, not 1). MaxInvent stores sync state in the isolated per-marketplace database so a crash on Amazon sync doesn't affect Temu sync.
Ongoing
Drift = time between a stock change in the pool and that change landing on the channel. MaxInvent measures drift every time it syncs and plots it per channel. Target: p95 under 20 minutes for every channel. If you see drift spiking above 30 min, it's a bug — investigate before it causes an oversell.
After following every step, you should be able to verify these outcomes:
Because each marketplace only knows about its own listings. Amazon's SP-API can't tell you that eBay just sold a unit — that information has to flow through a central pool. Any architecture that uses one channel as the source of truth will drift against the others.
In practice, 1-2 minutes per channel, limited by rate caps. For Amazon SP-API, 100 feeds/hour means realistically 1 feed every 40 seconds max. For Temu, the 4 req/sec limit caps you at around 2-3 min for a 1,000-SKU sync. Most UK sellers don't need sub-5-min sync — the cost of engineering it outweighs the oversell-prevention benefit.
Use both. Webhooks (event-driven push from your platform to the marketplaces) are faster but unreliable — they can silently fail. Polling (periodic sync) is slower but self-healing. The best architecture is webhook-first with a polling backstop every 15 min.
Two things. One: your platform should queue stock updates locally and flush them when the API recovers. Two: on the OTHER channels, you should NOT pause selling — they're still online. MaxInvent handles both automatically. Some older platforms just stop syncing everywhere when one channel fails, which is much worse.
It should. If SKU BUNDLE-A is made of 2x SKU-1 and 1x SKU-2, then the exposed stock of BUNDLE-A is min(floor(SKU-1/2), SKU-2). MaxInvent recalculates bundle stock on every component change and pushes to channels that list the bundle.
MaxInvent is built for UK multi-channel sellers. One stock pool across Amazon, eBay, Temu, TikTok Shop, Groupon and more — with the UK’s only native Temu courier label integration.
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