Developer – Billing Systems (REF5676S)

The largest ICT employer in Hungary, Deutsche Telekom IT Solutions (formerly IT-Services Hungary, ITSH) is a subsidiary of the Deutsche Telekom Group. Established in 2006, the company provides a wide portfolio of IT and telecommunications services with more than 5000 employees. ITSH was awarded with the Best in Educational Cooperation prize by HIPA in 2019, acknowledged as one of the most attractive workplaces by PwC Hungary’s independent survey in 2021 and rewarded with the title of the Most Ethical Multinational Company in 2019. The company continuously develops its four sites in Budapest, Debrecen, Pécs and Szeged and is looking for skilled IT professionals to join its team. Join a team responsible for one of the most business-critical areas within Deutsche Telekom's international group: billing systems . We deliver accurate, reliable, and flexibly configurable billing for fixed-line and mobile networks as well as mobile service providers — serving millions of customers. We're actively working to merge fixed-line and mobile billing into a single, modern platform, while gradually retiring legacy systems. That means you won't be maintaining a static, "legacy-only" system — you'll be part of a continuously evolving architecture undergoing real modernization. Your responsibilities will include: Developing and maintaining microservices (REST APIs and UI components) UI development using the Vaadin (Java) framework Writing automated tests (JUnit, Cucumber/Gherkin, Robot Framework) Building and optimizing CI/CD pipelines in GitLab Deploying and running Docker containers on Kubernetes / OpenShift Ensuring reliable communication between services and integrations Writing custom scripts for database synchronization (MongoDB) Creating technical documentation and knowledge resources Experience with Java / Spring Boot backend development Familiarity with our tech stack: Java, Spring Boot, MongoDB, Oracle DB, Shell, Maven Experience with tools such as GitLab, Jira, Grafana, Kiba