Legacy Software Modernization for a Telecom Company

Edvantis helped the Freenet Group upgrade its legacy infrastructure and migrate to a more agile microservices architecture in one year.


The Freenet Group is the largest network-independent telecom provider in Germany, offering a range of telecommunications, broadband, web, media, and TV services to its growing base of 8.3 million subscribers.

Freenet Key Figures at a Glance*

Freenet Key Figures

*as of date 31.12.2019

Four Main Brands in the Freenet Group:

  • mobilcom-debitel: One of the largest European providers of mobile phone services in Europe.
  • klarmobil.de: Mobile virtual network operator, offering discounted subscription plans.
  • GRAVIS: Authorized Apple reseller in Germany.
  • freenet.de: free email and cloud service.

As a market leader, striving to innovate, Freenet Group recognized the need to upgrade its legacy codebases early on. The original systems were built on Java 6 and Jboss (WildFly) application servers which no longer met its business needs.

Edvantis engineers were selected to assist Freenet with migrating and porting due to their significant experience with the Spring Boot framework, Java 11, and Mono+Flux libraries.

Solutions Delivered by Edvantis

The Edvantis team migrated and fully ported 16 legacy services to the new infrastructure in just 12 months.

Our main goal during migration was to preserve the business logic for all the applications to avoid any operational disruptions. Furthermore, our engineering team:

  • Performed code refactoring and improved its quality within the newer Java 11 version.
  • Upgraded legacy libraries using Spring Boot features.
  • Used a reactive approach to IT system modernization and helped the client migrate to a future-proofed microservices architecture, built on Java 11.

“Edvantis has intelligent people on board, competent and ready to get the job done. Their professionalism and approach to development has made for a good experience thus far, along with the speed and accuracy of their work.”

Thomas Reimann

In addition to development, Edvantis performed a set of essential QA services to ensure that the new systems function as intended. We delivered:

  • Code coverage reports that verified if the migrated biz-logic was fully covered by tests.
  • Integration testing to ensure there were no new bugs in the migrated code;
  • Static code analysis to double-check that the code is clean and ready for deployment.

Technologies Used

Java 11 / Spring Boot

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