Helps managing technology debt

Since microservices are smaller in size and have minimal dependencies, they allow the migration of services that are using end-of-life technologies with minimal cost.

Technology changes are one of the barriers in software development. In many traditional monolithic applications, due to the fast changes in technology, today's next generation applications could easily become legacy, even before releasing to production. Architects and developers tend to add a lot of protection against technology changes by adding layers of abstractions. However, in reality, this approach doesn't solve the issue, but, instead, it results in over-engineered systems. Since technology upgrades are often risky and expensive, with no direct returns for the business, the business may not be happy to invest in reducing the technology debt of the applications.

With microservices, it is possible to change or upgrade technology for each service individually, rather than upgrading an entire application.

Upgrading an application with, for instance, five million lines written on EJB 1.1 and Hibernate to Spring, JPA, and REST services is almost like rewriting the entire application. In the microservices world, this could be done incrementally.

As shown in the preceding diagram, while older versions of the services are running on old versions of technologies, new service developments can leverage the latest technologies. The cost of migrating microservices with end-of-life technologies will be considerably less compared to enhancing monolithic applications.