Senior Software Engineer (Backend)

As a Senior Backend Engineer, you will design and build core systems that power real-world energy processes - from billing to market communication.

You take ownership of complex domains, contribute to architectural decisions, and help evolve both our systems and engineering practices., Design and implement scalable solutions for billing, tariff models, and energy market processes.

• Shape system architecture Work across the full lifecycle - from design to deployment - ensuring maintainability, scalability, and correctness.

• Solve complex technical challenges Develop robust solutions involving data modeling, asynchronous processing, and distributed systems.

• Collaborate across disciplines Work closely with Product, Frontend, and DevOps to deliver cloud-based solutions and improve our platform.

• Drive improvement and innovation Bring in new ideas, improve engineering practices, and explore modern development approaches, including AI-assisted workflows.

• Modernize existing systems Help evolve and migrate legacy systems toward modern architectures., * Python, Django, Django REST Framework

• PostgreSQL, Redis

• Celery (async processing)

• Docker, Kubernetes

• GitLab CI/CD

• Robot Framework (testing)

• React (frontend)

We deploy continuously to Kubernetes and work with distributed systems handling complex, business-critical data.

• 5+ years of backend development experience
• Strong Python and Django expertise
• Experience designing and building REST APIs
• Experience with distributed systems / microservices
• Solid understanding of databases (PostgreSQL)
• Experience with Docker and CI/CD workflows
• Strong communication skills in English, * Experience with FastAPI, Pydantic, or Django Ninja
• Knowledge of Celery or similar async tools
• Experience integrating external systems (e.g. ERP, APIs)
• Familiarity with React / TypeScript
• Interest in energy markets or regulated domains

• Impact: Build software that directly enables renewable energy business models
• Ownership: Work on complex, meaningful systems with real-world impact
• Growth: Structured onboarding and continuous learning
• Flexibility: Flexible hours and hybrid work setup
• Benefits: Competitive compensation, Deutschlandticket
• Location: Modern office in Berlin Kreuzberg

Lumenaza develops powerful software to connect producers and consumers of green distributed energy, providing everyone access to the energy market. We unlock innovative businesses models based on green distributed energy resources, accelerating new energy. This enables businesses to increase core product sales and sell energy services to existing and new customers. Our platform significantly reduces time-to-market and cost-to-serve.We maximize value from renewable assets. Consumers benefit from knowing the clear origin of their energy and profit from innovative, individualized energy solutions