Ask HN: Any e-commerce firms that actively monitor themselves as real end users?

Ask HN: Are there any e-commerce platforms that actively monitor their platforms for end-user experience by actually purchasing stuff via real orders, at least the ordering and payment part?

Do large companies really monitor/test their platforms as real users, or is it just testing-inside-the-fence via simulated traffic?

If so, what could be the findings?

Just curious to know!