Syncing inventory between a WooCommerce (or similar) storefront and an external system — a POS, a warehouse management tool, a supplier feed, or a marketplace like Amazon/eBay — is one of the more resource-hungry recurring jobs a store runs, and it behaves very differently depending on where the store is hosted. Here's what actually determines whether an inventory sync runs reliably or quietly fails.
Why inventory sync is heavier than it looks
A sync job isn't one request — it's typically a scheduled process that loops through every SKU, checks or updates stock levels via a REST API call (to the external system, to WooCommerce's own REST API, or both), and writes changes back to the database. For a catalog of a few hundred SKUs this is trivial; for several thousand SKUs updated on a tight schedule, it becomes a sustained burst of CPU, database writes, and outbound API calls that can collide with normal site traffic if it runs during business hours.
Where it breaks on different hosting tiers
| Hosting tier | What typically goes wrong |
|---|---|
| Basic shared hosting | PHP execution time limits and memory caps kill long-running sync scripts mid-batch; WP-Cron (which only fires on page visi |