What I see in this thread is tons of people saying "the ideal of perfect billing cutoffs with no over-runs is impossible, which is why there are no billing cuto

What I see in this thread is tons of people saying "the ideal of perfect billing cutoffs with no over-runs is impossible, which is why there are no billing cutoffs" even though I've also seen lots of people point out that - to simplify - something is better than nothing, here. A $1k overrun past your billing cap is still way better than a $50k overrun - the cloud vendor is more likely to get paid in the end, and the customer is more likely to come away from the experience looking at it as an 'oops' instead of a catastrophic, potentially-finances-ruining 'i'm never touching this service again' incident. There are plenty of really challenging problems in computer science and we solve them with compromises every day while hitting demanding targets. If a SSL certificate expires we expect it to stop working, and if it's revoked we expect the revocation to take effect eventually. But it becomes a situation where these guarantees benefit small companies and independent developers but we suddenly can't solve similar problems? Fundamentally speaking if you can't afford to check against the billing cap every request, check every 10 requests. If 10 is too often, every 100. If 100 is too often, every 1000. Or check once per minute, or once per hour. Or compute a random number and check if it exceeds a threshold. The check can even be asynchronous to avoid adding intermittent latency to requests. Any of these are better than nothing and would stop the bleeding of a runaway service incident. It's unrealistic to expect small companies and independent developers to have someone on-call 24/7 and it's also unrealistic to expect that if you sell them $100k worth of stuff they can't pay for that they'll actually pay you somehow.