Google Cloud user here. A warning: If you ever happen to get, say, frontpage on reddit or techcrunch or other big boost to publicity, your site could be down until the next billing cycle (i.e. 24 hours) and you will have no way to fix it.
This bit me hard one day with appengine and lost us a ton of converting traffic, even though we tried to get the limit increased within ten minutes of the spike (and well before our limit was hit).
Even if the front door of the system didn't help you, we definitely shouldn't have been able to get you in a good state much quicker. My profile has Twitter and my DMs are open (I can give you my email there too).
Doing my kids dinner, so responses might be slightly delayed.
Its a problem with most cloud providers, but Google seems to be notorious for it.
"Company ignoring you? Send out a tweet, that'll work!"
And it blows my mind that it actually does. It's very sad.
You just really have to put some serious thought into what your daily limits should be, and add some reasonable alerting to detect surges. The tools are there and they're not terribly hard to use. It just tends to be an afterthought for most developers because this doesn't look like a customer feature.
Without these sorts of automated scaled services, the traditional behavior is "your app goes down". This is a big improvement!
This is hard for some things, but your startup failing because you didn't want to do it is much harder in the end.
It would be very difficult to build products in a reasonable amount of time if everything has to be coded defensively. I can build my app quicker, and remain sane, if I assume that the DB will always be available, and just fail if the DB isn't there. Same for things like S3 (which I think had only 1 large scale failure in recent history), Redis, etc...
There are APIs which can be unavailable and you need to work around those. For me, these are mostly third party services that I don't control. But then again, I'm not building the next Netflix. I don't have enough engineers to build an app that works with a chaos monkey!
Not the best approach for all applications, but has been good enough for most projects I've worked on. Just my 2 cents.
It's not an unreasonable request that for services which advertise the ability to scale up and down on demand, that the billing and billing limits should also be able to respond similarly.
How so? With a pay-as-you-go system, firing off warnings and giving a projection of their future costs (which is hard when startups tend to have spikey traffic) is about as good as you can do.
Edit: I should add that the common solution to controlling your billing in situations like this is having some overflow path built into your beta app ("Sorry, we're not taking new users at the moment" or the like).
In essence, settings and updating amount, rate and velocity ( speed of rate change ) caps on the fly.
Then I can set whatever tight limit I want to, and not worry about burning through too much cash because of some simple coding, or config error.
A bug almost cost us several tens of thousands of BigQuery costs when a dev accidentally repeated a big query every 5 seconds in an automated script, and while we still had budget warnings, it still cost us a fair bit of money. Even after this, I found it tricky to set/catch budgets for single services. I think I had to use stackdriver to be able to get any kind of warning.
It was in the ’blinking lights and sirens’- territory fast!
An account that goes from $0 spend to $30k in 72 hours should really trigger some kind of flag - even internally within google. What if they didn't have any kind of grant and weren't able to pay?