The sequence of WordPress hooks and database writes WooCommerce executes when processing an order at checkout. The pipeline runs on the server: validating the cart, processing payment through the gateway plugin, writing the order to the database, reducing stock, and triggering confirmation emails. A PHP error at any point in the pipeline stops it silently, which is why a customer can see a confirmation page while no order was recorded. Loupely captures the full pipeline event log to show exactly where it stopped.