Software Architect's Handbook

Sharing dependencies between microservices

Development teams should avoid sharing dependencies, such as frameworks and third-party libraries, between microservices. You may have multiple microservices that share the same dependency, so it is natural to think about sharing them on the host to make them centrally available.

However, each microservice should remain independent of other microservices. If we want to update the dependencies, we don't want to affect any other services. Doing so would increase the risk of introducing defects and will broaden the scope of the testing that will need to be conducted related to the change.

Sharing dependencies also introduces host affinity, which we want to avoid. Microservices should function independently ...