Are you a seasoned Java developer who thrives in technically demanding environments and enjoys the challenge of modernizing legacy systems? At NFON, we’re shaping the future of cloud telephony across Europe, and we're looking for an experienced Java engineer who can help us modernize, optimize, and scale our platform.As a Senior Java Developer, you’ll play a vital role in evolving our backend systems, from Java 7/8 to more modern stacks, while building robust solutions using industry-standard frameworks and tools.

• Modernize and migrate legacy Java systems, specifically transitioning from JDK 7 to JDK 8 and beyond.
• Take ownership of backend development using modern Java, with a focus on robust, maintainable, and scalable code.
• Drive improvements in our tech stack, including the replacement of OpenJPA with Hibernate.
• Collaborate closely with cross-functional teams in architecture, DevOps, and product to deliver secure and scalable RESTful APIs.
• Work in complex SQL environments (MariaDB) and contribute to data-heavy business logic.
• Support containerization efforts using Docker, and help define future infrastructure evolution (e.g., Kubernetes).
• Integrate and support OpenID Connect-based authentication and authorization mechanisms.
• Contribute to and improve our CI/CD pipeline, leveraging Git-based workflows.

• Strong communication skills in English, with the ability to explain complex ideas clearly.
• A collaborative mindset, you enjoy working closely with teammates and building strong relationships across functions.
• Extensive Java expertise, especially in JDK 7 and JDK 8, including hands-on experience with migration projects.
• Deep familiarity with core backend frameworks and build tools, especially: Spring Framework, Hibernate, Maven, Experience with other Java ecosystem tools is a plus.
• Strong SQL skills, particularly in MariaDB or similar relational databases.
• Experience working in modern development environments: Git, CI/CD pipelines, and automation tooling.
• A proactive mindset when it comes to modernizing systems, automating tasks, and reducing technical debt.
• Practical understanding of REST API design, and how to build secure and scalable service endpoints.

• Exposure to container orchestration tools like Kubernetes.
• Familiarity with infrastructure-as-code practices.
• Experience in telecom, VoIP, or platform engineering environments.

• Enjoy a fair and appropriate salary.
• Comprehensive health insurance coverage for you and your family.
• Benefit from 22 vacation days, exceeding the legal-required standard.
• The option to work from home up to 2 days per week.
• Work remotely from anywhere up to 20 days per year.
• Work in a cosy, modern office equipped with top hardware.
• Choose your device – Mac or Windows.
• We cover costs for e-learning courses to support your professional development.
• Enjoy organic fruit baskets, a smoothie bar, quality coffee, mate, and more.
• We are "Certified Family Friendly" and support a healthy balance between work, family, and private life.
• Be part of an agile organization where your ideas matter and you have the opportunity to take charge.