Senior Kotlin/Java Backend Engineer

We are looking for a Senior Kotlin/Java Backend Engineer who thrives in complex data-driven environments, learns new frameworks quickly, and contributes to the continuous improvement of our architecture and delivery practices.

The Market-wide Half-Hourly Settlement (MHHS) Program is a key initiative shaping the future of the UK energy market. The system enables the measurement and processing of electricity consumption data every half hour — providing a more accurate view of real energy usage. This drives fairer tariffs, supports renewable integration, and fosters a more efficient, data-driven energy ecosystem.

As a Backend Engineer, you will play a central role in building and maintaining the core data processing flows of the MHHS system, ensuring scalability, reliability, and accuracy of large-scale data operations. You’ll work within the IOps pod, collaborating with cross-functional teams to design, develop, and evolve high-performance backend services running on the JVM stack.

Responsibilities:

• Design, build, and maintain core backend components and data processing flows for the MHHS platform
• Implement reliable, efficient, and scalable services using Kotlin and Java (JVM)
  
• Work with frameworks such as Quarkus and Spring (DI) to develop and integrate backend services
• Apply ORM and persistence best practices using Hibernate
  
• Collaborate closely with other engineers, data specialists, and DevOps to ensure smooth system integration
• Contribute to the CI/CD pipeline and modern software delivery practices
• Ensure observability, fault tolerance, and performance optimization of backend services
• Participate in code reviews, architectural discussions, and continuous improvement of engineering practices
• Support Agile delivery through estimation, planning, and iterative value delivery
• Promote clean code principles, testing culture, and high engineering standards

Requirements:

• 5+ years of experience in backend development using Java and/or Kotlin
  
• Proficiency with Hibernate and relational databases (SQL, PostgreSQL)
• Hands-on experience with Spring Boot or Quarkus frameworks
• Experience with CI/CD pipelines, version control (Git), and Agile delivery practices
• Experience with Docker and cloud environments (AWS and/or GCP)
• Knowledge of Kafka, message queues
• Understanding of event-driven architecture and RESTful APIs
• Experience building reliable, scalable backend systems with a strong observability and security focus
• Excellent problem-solving and analytical skills
• Upper-intermediate English and effective communication in distributed teams

Would be a plus:

• TypeScript skills — ability to understand or contribute to backend code when needed
• Understanding of energy sector data flows