Software Architect's Handbook

Using the sidecar pattern

One of the options available to you when developing microservices is polyglot development. You have the flexibility to use multiple programming languages, runtimes, frameworks, and data storage technologies. Microservices are independently developed and deployed, allowing you to select best-of-breed technologies to accomplish the given task.

If your software system is taking advantage of polyglot microservices, it can make it difficult to maintain libraries for cross-cutting concerns. You would need one for each programming language that you are using, resulting in duplication of effort and a lower level of maintainability.

One solution to this problem is to use the sidecar pattern. The logic for cross-cutting concerns ...