[solatic]

Hard disagree. I've found that the best setup is two monorepos - one with feature/app code, and one with operations configuration.

The fundamental mismatch is the feature/app code will have longer testing times, stuff like Puppeteer and creating-infra-per-MR that just fundamentally takes a long time to run. But in ops, you need configuration to roll out quickly, maybe run an autoformatter and a linter or two beforehand and that's it. When you want to rollback, you don't need to wait for all your tests to run.

Yes you need to deal with versioning. You can just use automatic timestamps. You can write easy automation to push new timestamps to the ops/config repository when there are new releases in the app repository. The ops repository has minimal configuration to pull the latest version of the app repository and apply it, where the app repository includes infra and deployment scripts themselves.

[gugagore]

The problem you describe with waiting for tests for unrelated code changes (or potentially related but you want to skip it for the reasons you describe) is a problem that seems to deserve a solution even within a single monorepo.

What are the solutions? You would need multiple merge queues.

[solatic]

There isn't really a solution that preserves the vision and advantages of a monorepo. If infra, config, and code are stored in the same repository, then rolling back one necessarily means that the others are supposed to have been rolled back as well. When the version of the code is not a simple identifier pointing to the code but the code itself, there's simply no way to do that safely without recompiling and retesting the code. Same as when a change to code results in a revert to the infrastructure - run plan, run apply, wait for the slow infrastructure APIs, and that must happen before the change to code.

If you try to come up with fancy rules like forbidding changes to infra, config, and code in the same commit, then you're just cramming a polyrepo design into a monorepo, with much more fragility, because commits get rebased and squashed and etc.