Not all business domain models are equals, which is why different sets of technologies are needed. Since one microservice should only address the demands of one domain model, different services can adopt different technologies easily. It's common to find companies using different programming languages, frameworks, cloud providers, and databases to code their microservices. Furthermore, we have the ability to experiment with new technologies for small applications, which can then be used elsewhere. As a consequence of embracing new technologies, companies end up with heterogeneous applications, as shown in the following diagram:
Heterogeneous applications allow us to create specialized systems to solve specific business demands using the right set of technologies. As a result of this, we end up having small artifacts that are easy to deploy and scale in isolation.