Mid-level Backend Engineer (m/f/d)

🌐 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 50+ employees, with 46% being female and from 16+ nationalities, and steadily growing. Having raised of over €40 M in total, we are looking for passionate people to join us on our mission! 🚀

🇩🇪 Wir haben eine klare Mission: Wir bauen Europas führende Plattform für Energiemanagement, um faire und saubere Energie für alle zugänglich zu machen. ⚡

Unser Team ist vielfältig – wir sind über 50 Personen aus mehr als 16 Nationalitäten, mit einem Frauenanteil von 46 %. Und wir wachsen weiter!
Mit über 40 Mio. € an Finanzierung suchen wir nach motivierten Menschen, die gemeinsam mit uns die Energiezukunft gestalten wollen. 🚀

Your Mission

We are looking for a Mid-level Backend Engineer to join our team. You would be joining the Tech team, which currently is made up of twenty people, sixteen 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

• 3+ years of backend development experience.

• Strong experience with TypeScript.

• 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.

• Familiarity with CI/CD workflows (e.g., Docker, GitHub Actions).

• You can view our full tech stack here.

Nice to have

• Experience with AWS services (ECS, RDS (Aurora), S3, CloudWatch, Lambda) .

• 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.

Interview process

1. TestGorilla Assessment
   A short online assessment to help us understand your skills and working style.

2. Technical Interview with our Engineering Team
   A conversation focused on your technical abilities, problem-solving approach, and practical experience.

3. Interview with the People Team
   Meet the People Lead to explore Ostrom's values and our company culture.

4. Interview with our Head of Engineering
   A conversation with our Head of Engineering to explore your experience, working style and alignment with the role.

5. Co-Founder Interview
   A final conversation to discuss alignment, culture, ownership, and your impact on Ostrom as a whole.

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.

🌐 About Us

We’re Germany’s fastest-growing digital green energy provider and a Certified B Corp™ , driving the energy transition by making renewable energy more accessible and inclusive.

How? Through variable tariffs, dynamic pricing, smart EV charging, heat pump and solar optimization, and Germany’s first virtual power plant: NeoGrid™.

At Ostrom, you’ll work in a dynamic, open environment where you can be yourself, take on challenges, and grow both personally and professionally.

🌱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.

📈 VSOP: On top of offering a competitive salary you will have access to company shares to ensure you can truly be part of the journey.

👭 Trust-based Team: A truly flat hierarchy and transparent company culture, where everyone’s voice matters.

💪🏽Benefits: An annual learning budget, company-pension scheme, company events, discounted gym membership, public transport ticket, e-bike or e-moped, Futurebens or monthly vouchers - the choice is yours.

💬 Stay In The Loop: We believe in transparent communication — from weekly town halls and quarterly updates to regular retrospectives. Got feedback or an idea? We’re all ears.

🤝 Work Together, Celebrate Together: We thrive on collaboration. Wins are shared and so are the celebrations from monthly happy hours to team trips and company events.

🌍 Work Your Way: Whether you prefer the office, your home desk, or a sunny spot in Sardinia — you work where you work best.

🚀 Learn By Doing: We grow together with personal development paths, learning budgets, and regular knowledge-sharing sessions. Try things out, learn along the way, and keep moving forward.

🇩🇪 Über Uns

Wir sind der am schnellsten wachsende digitale Ökostromanbieter mit B Corp™ Zertifizierung in Deutschland – und treiben die Energiewende aktiv voran. Unser Ziel: Erneuerbare Energie für alle zugänglich und inklusiv machen.

Wie? Mit variablen Tarifen, dynamischem Strompreis, Smart EV Charging, Optimierung von Wärmepumpen und Solaranlagen sowie Deutschlands erstem virtuellen Kraftwerk: NeoGrid™.

Bei Ostrom arbeitest du in einem offenen, dynamischen Umfeld, in dem du du selbst sein kannst, Herausforderungen annimmst und dich kontinuierlich weiterentwickelst.

🌱 Nachhaltigkeit, die zählt: Mit deinem Wechsel zu Ostrom unterstützt du aktiv die Energiewende. Unsere Kund*innen helfen im Schnitt, jährlich 1,5 Tonnen CO₂ gegenüber dem deutschen Durchschnittsstrommix einzusparen.

📈 Wertschätzung, die sich auszahlt: Neben einem attraktiven Gehalt erhältst du bei uns VSOPs – Unternehmensanteile, mit denen du direkt am Erfolg von Ostrom beteiligt bist.

👭 Teamkultur auf Augenhöhe: Bei Ostrom leben wir flache Hierarchien und eine offene Feedbackkultur. Deine Meinung zählt – vom ersten Tag an.

💪🏽 Benefits: Du erhältst ein flexibles Paket mit vielen Extras – von einem jährlichen Weiterbildungsbudget, über eine betriebliche Altersvorsorge, bis hin zu vergünstigten Fitnessstudio-Mitgliedschaften, einem Jobticket oder deinem eigenen E-Bike bzw. E-Roller. Alternativ wählst du monatliche Gutscheine oder FutureBens – du entscheidest, was dir wichtig ist.

💬 Transparenz: Ob in wöchentlichen Townhalls, vierteljährlichen Updates oder offenen Retrospektiven – wir glauben an klare Kommunikation und kontinuierlichen Austausch.

🤝 Erfolge feiern wir gemeinsam: Teamarbeit steht bei uns im Mittelpunkt – und genauso feiern wir auch unsere Erfolge: mit regelmäßigen Happy Hours, Team-Ausflügen und unvergesslichen Company Events.

🌍 Work you way: Ob im Berliner Büro, im Homeoffice oder remote unter der Sonne – bei uns arbeitest du dort, wo du am produktivsten bist.

🚀 Wachse mit uns: Persönliche Entwicklung ist bei Ostrom keine Floskel. Wir unterstützen dich mit Lernbudgets und Raum zum Ausprobieren – damit du dich fachlich und persönlich kontinuierlich weiterentwickeln kannst.