Senior Java Developer

About the Position

Senior Java Developer

At Optimax Energy, we have been developing smart solutions for automated trading systems and promoting the transition to green energy for over 10 years. This makes us a leader in international electricity trading.

Our culturally diverse team shares a common vision and fosters a culture of appreciation and equal opportunities. We believe that we can achieve extraordinary things if we develop freely. That's why we place great value on a healthy work-life balance and encourage creative freedom.

We embrace diversity, equality, and inclusion. Different perspectives and backgrounds strengthen our team and lead to creative solutions. To achieve this, we create an appreciative working environment that recognizes the uniqueness of all employees and retains talent in the long term.

In order to actively shape the future of the energy sector, we are looking for outstanding, committed individuals who share our vision and corporate culture.

Responsibilities

As a Java Developer in our Integrators team, you will play a crucial role in maintaining and enhancing our existing services while driving innovation by:

• Gathering and refining requirements by directly collaborating with stakeholders.
• Developing new features for the trading platform.
• Writing unit and integration tests, maintaining high code coverage.
• Maintaining and troubleshooting services that provide essential market data for trading decisions, ensuring system reliability, scalability, and overall software quality.
• Conducting code reviews and collaborating with peers to maintain high-quality standards.
• Participating in workshops and encouraging knowledge sharing.
• Writing technical documentation.

Requirements

Must-Haves

• Degree in computer science or comparable field of study
• At least 5 years of professional software development experience, including 3+ years in Java (senior level).
• Understanding of Object-Oriented software design patterns and CLEAN code principles.
• Familiarity with threads, Java Executors, concurrency models, and asynchronous programming.
• Experience in implementing efficient data structures and data processing.
• Familiarity with unit and integration testing.
• Good communication skills in English (at least B2).
• Residence in Germany and a valid work permit.

Nice-to-Haves

• Experience building and managing Java projects with Maven.
• Experience with Docker, Jenkins, CI/CD pipelines.
• Experience designing and consuming API services.
• Experience with message brokers and asynchronous messaging in general (e.g., RabbitMQ, Apache Kafka).
• Knowledge of Spring Framework (Boot, Web, Messaging, Security).
• Familiarity with agile methodologies (Scrum, Kanban).
• Basic SQL skills for writing queries and understanding relational databases.
• Performance tuning, profiling, and optimization.
• Understanding of common software architecture notations and standards (UML, C4).
• Background in energy markets or trading.

We Offer

Salary: 65,000–75,000€/year - depending on your experience

Health & well-being:

• Freshly cooked lunch every day
• Massages and Pilates in the office
• EGYM Wellpass
• Sports and mobility offers, such as subsidies for a new bike

Flexible working arrangements and benefits:

• 30 days paid vacation
• Flexibility in working hours depending on company needs
• Additional vacation for the honeymoon
• Subsidies for childcare

Team culture and working atmosphere:

• Regular team events (game night, table tennis tournament, excursions, etc.)
• Work in a mission-oriented, international team that values diversity and equality
• Working atmosphere with open doors and flat hierarchies
• Modern, green office in the heart of Leipzig

Professional development and further training:

• Independence and responsibility in project management
• 10% of weekly working time for personal and professional development

About the Company

At Optimax Energy, we have been developing smart solutions for automated trading systems and promoting the transition to green energy for over 10 years. This makes us a leader in international electricity trading.

Our culturally diverse team shares a common vision and fosters a culture of appreciation and equal opportunities. We believe that we can achieve extraordinary things if we develop freely. That's why we place great value on a healthy work-life balance and encourage creative freedom.

We embrace diversity, equality, and inclusion. Different perspectives and backgrounds strengthen our team and lead to creative solutions. To achieve this, we create an appreciative working environment that recognizes the uniqueness of all employees and retains talent in the long term.

In order to actively shape the future of the energy sector, we are looking for outstanding, committed individuals who share our vision and corporate culture.