> you are doing end-to-end testing, the question is whether you're doing it before production or if your customers are doing it for you. This reminds me of the

> you are doing end-to-end testing, the question is whether you're doing it before production or if your customers are doing it for you. This reminds me of the point I've seen made elsewhere: E2E tests can be complemented by use of monitoring metrics, healthchecks, etc. for providing confidence that the system is working as intended (or for spotting cases where it's not working as intended).