Senior Java Developer (m/f/d) for Energy Trading ID26671-0

For a project in we are looking for a:



Senior Java Developer (m/f/d) for Energy Trading ID26671-0



Duration : 20.10.2025 – 31.12.25

Volume : 75h onsite, 450 h remote

Location : Hybrid (Remote & Onsite in Essen, Germany, ~2 days/month



Job Description:

The PTT (Portfolio & Trade lifecycle Technologies) team is looking for a Senior Java Software Developers to join as external consultant our fast-paced, innovative-driven team as consultants supporting cutting-edge projects in the energy trading sector. We are offering a hybrid working environment - predominantly remote, with collaborative onsite sessions around two days per month.



Key Responsibilities:

• Design, develop, and maintain scalable Java applications for energy trading solutions.

• Work primarily with Spring Boot, Project Reactor, and Apache Kafka to build robust, event-driven systems.

• Collaborate closely with cross-functional teams to define, design, and ship new features.

• Write clean, efficient, and testable code, following industry best practices.

• Participate in code reviews and contribute to continuous improvement of our development processes.

• Stay up to date with emerging trends and technologies, share knowledge within the team



Requirements:

• Proven experience (5+ years) as a Java developer in a professional environment.

• Strong expertise in Spring Boot and knowledge of developing RESTful APIs.

• Experience with Time Series data, especially with time zone handling and DST.

• Hands-on experience with messaging systems, especially Apache Kafka.

• Familiarity with reactive programming (ideally with Project Reactor).

• Experience in building and maintaining production-grade, distributed systems.

• Excellent problem-solving skills, with a proactive and self-driven approach.

• Effective communicator in English; German is a plus.

• Willingness and ability to join onsite meetings in Essen, Germany once per month



Preferred Qualifications:

• Experience in energy trading or financial trading industries.

• Knowledge of cloud technologies and deployments (e.g., AWS, Azure, Kubernetes).

• Background with CI/CD pipelines and DevOps practices.

• Exposure to microservices architecture and containerization (Docker).

• Bachelor’s or master’s degree in computer science, Engineering, or a related field.

• Openness to explore and pilot new tools and frameworks.



Application and contact:

If we have aroused your interest, we look forward to receiving your detailed Word profile, stating your hourly rate, EU-DSGVO agreement and availability to

bewerbung@c4-energy.com



Thank you in advance and best regards

Your C4 Group



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