You can. If you set up the modular DAG as I mentioned above, you can now set up service boundaries between the leaves of the DAG. E.g. parts of the code call other parts of the code as a service. You then version and deploy the same codebase separately.

Say you have Libraries A, B, and C, where B and C depend on A and not one another. You can have B call into C via a service, just as you would in a microservice. Now B and C can be versioned and deployed independency. You can also deploy updates to Library A incrementally, tying it to the B and C deployments.

> a monolith you can't roll back "a part" of the app to the latest version if you pushed multiple unrelated features at once.

git revert <bad commit>

Well yes, but if you used a compiled language you have to make a new release based on this commit.

What I mean is, if you have v2 of your software that introduces a bugfix for module A that's perfectly fine and a bugfix for module B that breaks everything, you can just roll back just module B directly with your deployment pipeline.

There's no need to go back to the code base and make a new release.