In what way? Versioning helps pin shared libraries so they are not inadvertently updated. However, when you have 2 services A and B using the same library, changes to the library, if they are not updated in both services, may lead to the services being unable to talk to one another. e.g. Suppose service A and B use library L. But the authors of library L decided to rename a certain field in the JSON of HTTP calls that are crafted by the library. Now, unless both A and B update to the new version, they may not be able to talk to one another, so each has to coordinate their efforts to either hold off using the new version, or deploy the new version at the same time.