Public Cloud (AWS, Azure, etc) is a very different thing than on-prem infrastructures. The low orbit view of the sector is that this is entirely intentional: create a new way of doing things to enable businesses to focus on what they're good at. A lot of high executives get that message and embrace it... until it comes time to integrate this new way with the way things have always been done. Then we get some problems.
The view from 1000ft is much different than the one from 250 miles up.
From my point of view, there are two big ways that integrating public cloud will cause culture problems.
- Black-box infrastructure.
- Completely different cost-model.
I've already spoken on the second point so I won't spend much time on it here. In brief: AWS costing makes you pay for what you use every month with no way to defer it for a quarter or two, which is completely not the on-prem cost model.
Black-box infrastructure
You don't know how it works.
You don't know for sure that it's being run by competent professionals who have good working habits.
You don't know for sure if they have sufficient controls in place to keep your data absolutely out of the hands of anyone but you or nosy employees. SOC reports help, but still.
You may not get console access to your instances.
You're not big enough to warrant the white glove treatment of a service contract that addresses your specific needs. Or will accept any kind of penalties for non-delivery of service.
They'll turn your account off if you defer payment for a couple of months.
The SLA they offer on the service is all you're going to get. If you need more than that... well, you'll have to figure out how to re-engineer your own software to deal with that kind of failure.
Your monitoring system doesn't know how to handle the public cloud monitoring end-points.
These are all business items that you've taken for granted in running your own datacenter, or contracting for datacenter services with another company. Service levels aren't really negotiable, this throws some enterprises. You can't simply mandate higher redundancies in certain must-always-be-up single-system services, you have to re-engineer them to be multi-system or live with the risk. As any cloud integrator will tell you if asked, public cloud requires some changes to how you think about infrastructure and that includes how you ensure it behaves the way you need it to.
Having worked for a managed services provider and a SaaS site, I've heard of the ways companies try to lever contracts as well as lazy payment of bills. If you're big enough (AWS) you can afford to lose customers by being strict about on-time payment for services. Companies that habitually defer payment on bills for a month or two in order to game quarterly results will describe such services as, 'unfriendly to my business'. Companies that expect to get into protracted SLA negotiations will find not nearly enough wiggle room, and the lack of penalties for SLA failures to be contrary to internal best practices. These are abuses that can be levered at startup and mid-size businesses, quite effectively, but not so much at the big public cloud providers.
It really does require a new way of thinking about infrastructure, at all levels. From finance, to SLAs, to application engineering, and to staffing. That's a big hill to climb.