As organizations grow, they often transition from monolithic codebases to microservices to manage increased complexity and developer efficiency. While monolithic structures allow for rapid feature addition by leveraging shared code, they can become unwieldy as teams expand. Transitioning to microservices allows developers to work independently but introduces challenges such as network call complexity and redundant solutions. To mitigate these issues, shared internal libraries for concerns like logging, tracing, and dependency management can streamline development and enhance consistency. At CircleCI, shared libraries are managed like third-party libraries, with version control to ensure compatibility. However, this approach requires careful management to avoid update bottlenecks and maintain backward compatibility. By dedicating teams to manage these libraries, organizations can ensure they provide benefits across multiple services, reducing costs and increasing efficiency in building and maintaining microservices.