There's no way to implement a hard limit without getting in the middle of your system in ways that (a) alter the system design, (b) in ways you cannot correct for, and (c) not for the better.

Of course there is. If someone hits their spending limit, asynchronously shut off the services (using the same API call that your customers can use, so no need to alter the system).

Then apply the hard limit in the billing code. If it took a minute or two to shut off all the instances, maybe the customer's bill should have been $1.001M instead of $1M, but cap the bill to $1M anyway. Given their profit margins of x,000% I think they can afford the lost pennies.

In my experience every AWS service I've worked with has an API to destroy the resource, eg destroy RDS instance without backup, terminate EC2, etc. I want it to irrecoverably destroy everything in my account when it hits the limit, no questions asked.

> There's no way to implement a hard limit without ...

I don't believe that for a minute.

You know why ?

Let's turn it on its head. What happens if the credit card on your AWS account expires or is frozen ?

You think AWS are going to continue letting you rack up money with no card to charge against ?

I betcha they'll freeze your AWS assets the nanosecond they can't get a charge against the card.

The mechanism for customer-defined hard limits is basically no different.

From experience they will let you spend tens of thousands of dollars a month without a valid payment method.

Like many times more than you've ever even spent with them.

I mean it's like 6 months of that before you even get your first non-standard form email.