Scaling a large codebase requires careful consideration of various factors such as organization, reuse, experimentation, and deployment. Monorepos are an effective way to organize and reuse code across teams, enabling faster iteration velocity and reduced build times. Feature flags provide confidence in releasing new code without affecting existing versions, while incremental builds with Turborepo enable reusing work that's already been completed, reducing the need for repeated computations. Skew protection ensures that different versions of the application run on client and server, preventing version skew issues. By adopting these strategies, teams can achieve faster iteration velocity, adopt new technology more easily, and share code across different parts of the UI, ultimately leading to a successful transformation of their large codebase.