Senior Backend Engineer

We are on the mission to build Europe’s leading energy management platform to provide fair, clean energy to everyone. ⚡

We’re a diverse team of 47+, with 47% being female and from 16+ nationalities, and steadily growing. Having raised a total of over €23 M, we are looking for passionate people to join us on our mission! 🚀

Your Mission

We are looking for a Senior Backend Engineer to join our team. You would be joining the Tech team, which currently is made up of sixteen people, twelve engineers, and four in Product. As part of a cross-functional team, you will be focused on projects related to new business alongside projects to reduce our Operations load, ensuring we can grow faster with a lean team.

What you will be working on

• Design and build backend solutions from scratch.
• Take part in tech stack decisions—choosing the best tools, frameworks, and processes for the team.
• Help develop a scalable platform for the renewable energy sector using modern technologies.
• Integrate new product lines like smart meters, dynamic pricing, EV charging, and more.

What we're looking for

• 5+ years of backend development experience.
• Strong experience with TypeScript and/or Python.
• Confident designing and building APIs.
• Solid understanding of relational databases.
• Commitment to writing clean, testable code (unit, integration, and E2E testing).
• Comfortable working on greenfield projects and building systems from the ground up.
• Strong communication skills and fluency in English.
• You can view our full tech stack here.

Nice to have

• Experience with AWS services (ECS, RDS (Aurora), S3, CloudWatch, Lambda).
• Familiarity with CI/CD workflows (e.g., Docker, GitHub Actions).
• Experience with React or React Native, or willingness to learn new technologies and take on full-stack tasks when needed.
• Experience using AI tools (e.g., for debugging, documentation, testing)—we value developers who integrate AI into their daily workflow to boost productivity, but also have a practical mindset — we’re not into vibe coding. We appreciate thoughtful engineering and clear thinking.

Why Ostrom?

• Environmental Impact: Each customer who switches to Ostrom on average helps offset 1.5 tons of CO2 emissions per year compared to the average German energy mix.
• Flexibility: We offer a hybrid work model with a dog-friendly office in Berlin, Mitte, in case you prefer working in the office.
• Relocation package: If you want to move to Germany, we offer a visa and relocation support.
• Trust-based Team: A truly flat hierarchy and transparent company culture, where everyone’s voice matters.
• Personal development: You receive an annual growth budget, encompassed with frequent development 1:1’s and development cycles held twice a year.
• Benefits: From monthly team events to discounted gym membership, ticket for public transport, e-Moped or e-Bike via Dance, Futurebens, and monthly vouchers.