Senior Java Developer

Ref: #74231 Leipzig, Germany (On-site | 1 day/week remote by arrangement) Full-timeAbout the CompanyJoin a fast-growing technology company at the forefront of the European energy transition. For more than a decade, the business has been developing highly scalable software and automated trading systems that support one of Europe's most advanced energy trading operations.You'll join an international engineering team where software has a direct commercial impact, working in an environment that values technical excellence, collaboration, autonomy and continuous learning.The RoleYou'll become part of the team responsible for the core data integration and processing platform that powers real-time algorithmic trading.The team develops high-performance services that connect with external market operators, process large volumes of real-time data and enable expansion into new international energy markets.Your responsibilities will include:Designing and developing backend services in Java Building new features for a highly available distributed platform Integrating with external APIs and real-time data sources Maintaining reliable, scalable production systems Writing unit and integration tests Participating in code reviews and technical design discussions Collaborating closely with product and business stakeholders Producing technical documentation and sharing knowledge across the engineering team Technology StackBackendJava Spring Boot MySQL ClickHouse Messaging & IntegrationApache Kafka RabbitMQ WebSockets REST APIs JSON XML CSV DevOps & InfrastructureKubernetes Docker GitLab CI/CD Jenkins Maven SonarQube TestContainers MonitoringGrafana Micrometer Graylog RequirementsEssentialDegree in Computer Science or similar technical discipline 5+ years of software engineering experience 3+ years of professional Java development Strong understanding of object-oriented design and clean coding principles Experience with multithreading, concurrency and asynchronous programming Experience designing efficient data processing solutions Unit and integration testing experience Strong English communication skills (B2+) Based in Germany with a valid work permit Nice to HaveSpring Framework (Boot, Web, Messaging, Security) Maven Docker Kubernetes CI/CD pipelines REST API design Event-driven architectures Kafka and/or RabbitMQ SQL and relational databases Performance optimisation and profiling UML or C4 architecture modelling Agile development (Scrum/Kanban) Experience within energy, utilities, trading or financial systems Working ModelThis is an office-first engineering environment where collaboration and technical discussions happen primarily in person.Based in Leipzig Typically one remote working day per week Applicants must already be based in Germany and possess valid work authorisation BenefitsHealth & WellbeingFreshly prepared daily lunch Wellness initiatives including fitness and health programmes Sports and mobility benefits Work-Life Balance30 days annual leave Flexible working hours Additional leave for life events Childcare support Learning & Development10% dedicated learning time each week High levels of ownership and autonomy Professional training and continuous development opportunities CultureInternational engineering team Flat hierarchies and open communication Regular social events and team activities Modern office in central Leipzig This role would particularly suit a Senior Java Engineer who enjoys building distributed backend systems, integrating real-time data sources, and working on software that directly impacts a mission-critical, high-performance platform.