Basically I did exactly this :) I created a tool that helps you deploy your static (and hybrid!) app, with a few more features like creating environments, specifying remote configuration and staged rollouts. It took me a year part time, all by myself. Check it out here: https://www.stormkit.io. Basically, you gotta have a nice understanding of the cloud providers, some network knowledge, a lot of backend knowledge and a descent frontend knowledge if you want to compete with their awesome UX :) - Obviously, Netlify has a team behind it, but despite that I believe I did a good job.
If you're tired of rising cloud bills or want full control over your CI/CD pipeline, you can now run Stormkit on your own infrastructure.
GitHub: https://github.com/stormkit-io/stormkit-io
I'd love feedback from the HN community, especially on docs, self-hosting UX, and what features matter most for production use.
Happy to answer any questions about the architecture, trade-offs, or differences from other tools.