It depends on your company. For new startups, I'd stick with delivering your product over building your own cloud services on top of EC2/S3. At my last startup

It depends on your company. For new startups, I'd stick with delivering your product over building your own cloud services on top of EC2/S3. At my last startup, the engineering head shared the Not-Invented-Here view. We couldn't use any handy services. We had to run our own Cassandra and everything else services. It was a huge time sink for a small team that didn't deliver differentiating value. At my current startup, we're almost 100% serverless on SaaS providers. We operate a thousand or more nodes with no ops team (a couple engineers know ops, when needed). We leave the complexity of scaling an maintenance to our cloud vendor's autoscaling services. Sure, we could reduce our opex in places by trying to roll our own, but the ability to have the vast majority of engineers delivering customer product, rather than reinventing the wheel is more valuable to us than fear of vendor lock-in. If our cloud vendor wanted to jack rates, we'd take the necessary action, which we've done before when we banged a service in a week that a vendor was going to hold us over a barrel for, then dropped the vendor.