Software Architect's Handbook

Polyglot persistence

Similar to polyglot programming, there is the concept of polyglot persistence, in which multiple persistence options are used within a single application. Different data storage technologies are better suited to different tasks, and microservices allows you to take advantage of that.

Each microservice is in charge of its own data storage, so it can choose the best data storage technology based on what it is trying to achieve. The following diagram depicts two microservices, each with its own database:

A microservice dedicated to providing product recommendations based on friends, ratings, and prior purchases would be ideal ...