I agree with this and do the same for a, b, c. It wouldn't surprise me at all to see projects treating Docker based jobs / pipelines like they're deterministic

I agree with this and do the same for a, b, c. It wouldn't surprise me at all to see projects treating Docker based jobs / pipelines like they're deterministic. Unless you learn how everything interacts and are really careful it's very difficult to create repeatable builds with GitLab CI (and most other CI) because of what you say in d. If you can't run a build with your internet disconnected, it's not repeatable and you don't own it. The thing is it's MUCH better for companies like GitLab and GitHub to get you locked in to their SaaS build systems, so simple, repeatable, offline builds will never be a priority. The harder it is, the better it is because they can charge you more money to "manage" it. I have no idea how someone looks at a system like GitHub Actions and likes it. To me it seems obvious what's going on a GitHub. Eventually Microsoft is going to marry a bunch of tech together (ex: GitHub, Visual Studio Online, GitHub Actions, Azure Resource Manager) and everyone will be so hyped about how easy it is to click a button and have dev, build, deploy "just work" that they'll blindly give up control of their development and build environment. Just look at how easy it was for Apple and Google to convince developers to give up their ability to deploy apps without being blessed.