Senior Java Developer

Senior Java Developer

Leipzig, Germany (On-site | 1 day/week remote by arrangement)
Full-time

About the Company

Join 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 Role

You'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 Stack

Backend

• Java
• Spring Boot
• MySQL
• ClickHouse

Messaging & Integration

• Apache Kafka
• RabbitMQ
• WebSockets
• REST APIs
• JSON
• XML
• CSV

DevOps & Infrastructure

• Kubernetes
• Docker
• GitLab CI/CD
• Jenkins
• Maven
• SonarQube
• TestContainers

Monitoring

• Grafana
• Micrometer
• Graylog

Requirements

Essential

• Degree 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 Have

• Spring 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 Model

This 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

Benefits

Health & Wellbeing

• Freshly prepared daily lunch
• Wellness initiatives including fitness and health programmes
• Sports and mobility benefits

Work-Life Balance

• 30 days annual leave
• Flexible working hours
• Additional leave for life events
• Childcare support

Learning & Development

• 10% dedicated learning time each week
• High levels of ownership and autonomy
• Professional training and continuous development opportunities

Culture

• International 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.