Q: Your company transitions entirely to a massive Monorepo housing 50 microservices. A developer alters the `README.md` in the root directory. Suddenly, 50 individual CI/CD pipelines trigger simultaneously, deploying all 50 services to production. How do you architect the CI to intelligently prevent this?

Monorepos require highly intelligent Path Filtering and Dependency Graph Analysis.

• Path Filters: In GitHub Actions (paths:) or GitLab (rules: changes:), explicitly restrict service deployments to trigger *only* if code actually changes physically inside that service's highly isolated directory (src/services/service-a/**).
• Dependency Graphing: This easily breaks if service-a relies heavily on a shared library (src/libs/auth). If auth changes, service-a *must* confidently rebuild. Tools like Nx, Bazel, or Turborepo are absolutely mandatory here. They mathematically generate an internal AST dependency graph. If a commit touches auth, the tool intelligently analyzes the graph and explicitly triggers builds strictly for the specific subset of dependent microservices, entirely ignoring the other 49.