The Senior Software Developer (Java Application Developer) will design, develop, and maintain mid-size to complex, scalable applications in a cloud-native, microservices-based environment at Deutsche Telekom IT Solutions Slovakia. This role is central to migrating business logic from a legacy billing system into a modern event-driven streaming platform built on Quarkus and Kafka, enabling scalable digital transformation across the Telekom domain.
What You'll Do
- Collaborate with stakeholders (business, product, architects) to understand requirements and translate them into scalable technical solutions
- Design and develop backend applications and microservices in a cloud-native environment
- Contribute to the migration of business logic from a legacy billing system into a modern event-driven architecture (Quarkus + Kafka)
- Design and implement REST APIs and event-driven communication between services
- Analyze requirements and propose robust, maintainable architecture solutions with focus on scalability and performance
- Estimate development effort, plan implementation, and support delivery planning
- Develop high-quality, clean, and testable code using Java (preferably Java 17)
- Ensure code quality through testing, reviews, and best practices
- Participate in CI/CD pipelines, deployments, and release management
- Support application operation (L2/L3), including troubleshooting, bug fixing, and performance optimization
- Create and maintain technical documentation (architecture, APIs, flows)
- Ensure security and compliance with internal standards
- Proactively identify risks, perform root cause analysis, and drive improvements
- Act as a senior team member, contributing to architecture decisions and mentoring junior developers
- Share knowledge within the team and contribute to continuous improvement of development practices
What We're Looking For
- Develops new and maintains existing applications using modern technologies (primarily Java)
- Works independently or as part of a project team on designing, developing, and building mid-size to complex, scalable applications in a cloud-native, microservices-based environment
- Contribute to the migration of business logic from a legacy billing system into a modern streaming platform built on Quarkus and Kafka
- Design and develop backend applications and microservices in a cloud-native environment
- Design and implement REST APIs and event-driven communication between services
- Analyze requirements and propose robust, maintainable architecture solutions with focus on scalability and performance
- Estimate development effort, plan implementation, and support delivery planning
- Develop high-quality, clean, and testable code
- Ensure code quality through testing, reviews, and best practices
- Participate in CI/CD pipelines, deployments, and release management
- Support application operation (L2/L3), including troubleshooting, bug fixing, and performance optimization
- Create and maintain technical documentation (architecture, APIs, flows)
- Ensure security and compliance with internal standards
- Proactively identify risks, perform root cause analysis, and drive improvements
- Act as a senior team member, contributing to architecture decisions and mentoring junior developers
Nice to Have
- Java 17 (preferably)
Technical Stack
- Java
- Java 17
- Quarkus
- Kafka
- microservices
- cloud-native
- REST APIs
- event-driven architecture
- CI/CD
Team & Environment
- team of experienced senior developers
- project team focused on migration initiative
