Senior Software Engineer (Backend) (m/w/d)

This is us

Lumenaza is a green-tech company building software for the decentralized energy world. Our platform enables energy providers to manage billing, market communication, and energy data --- supporting renewable energy business models at scale.

We are driven by a clear mission: accelerating the transition to a sustainable energy system. At the same time, we value diversity, collaboration, and continuous learning.

Your tasks

Your Role

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.

What You'll Do

• Build and own core backend systems 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.

Your profile

Core Requirements

• 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

Nice to Have

• 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

Our Tech Stack

• 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.

Your team

We offer you this

• 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

We strongly encourage applications from underrepresented groups in tech and are committed to building an inclusive environment.

Apply now!