>I just don’t enjoy the infrastructure side that much.
That's fair, that's totally your right.
However, you're talking about absolute cost and unfortunately you're examples weave through true and false quite frenetically.
> - we don’t want to maintain our own build servers. We just use CodeBuild with one of the prebuilt Docker containers or create a custom one. When we push our code to Github, CodeBuild brings up the Docker container, runs the build and the unit tests and puts the artifacts on S3.
Like all things business, "want" and "cost" are different, in this case, depending on your size of course, it could easily be cheaper to have a dedicated "build engineer" maintaining a build farm. This is how the majority of people do it. (I work in the video games industry, it's _MUCH_ cheaper to do it this way for us)
> - We don’t want to maintain our own messaging, sftp, database, scheduler, load balancer, oath, object storage, servers etc. We don’t have to, AWS does that.
Again, those are "wants", TCO can be much lower when out of the cloud. But again, depends on scale. (as in, lower scale is cheaper on cloud, not larger scale).
> - We don’t want to manage our own app and web servers. We just use Lambda and Fargate and give AWS a zip file/docker container and it runs it for us.
I mean, 1 sysadmin can automate/orchestrate literally thousands of webservers.
>- We need to run a temporary stress test environment or want to do a quick proof of concept, we create s Cloud Formation template, spin up the entire environment, run our tests with different configurations and kill it. When we want to spin it up again, we just run the template.
Yes, this is a real strength of cloud.
> We don’t have to pay for a staff of people to babysit our infrastructure between our business support contract with AWS and the MSP, we can get all of the troubleshooting and busy work support as needed.
Yes, but you are paying "overhead" for all of that, and not having talented engineers on your payroll who understand your business critical systems is, in my opinion, foolish.
I've dealt with vendor support and it's incredibly hit and miss, and it's much more "miss" when you're a smaller customer to the vendor. Of course, this is anecdotal.