Junior Backend Engineer (f/m/x) Platform (API & Data)

About the role

Hamburg Hybrid (2–3 days/week onsite) | €55.000 - 60.000 p.a. | 30 Days Vacation | English B2 Are you enthusiastic about intelligent and effective software solutions to the energy transition? Join us at suena energy as a  Junior Backend Engineer (f/m/x) and become an essential part of our new platform team. You’ll work side-by-side with experienced engineers on both APIs and data-driven backend systems, gaining hands-on experience in everything from database design to real-time integrations for next-generation energy trading. This is your chance to learn, grow, and have a real impact in a friendly, ambitious, and sustainable tech environment. suena energy is a green tech startup specializing in algorithmic energy trading for energy storage systems and renewables. Our vision: a world where clean energy is used reliably, economically, and intelligently. Our AI-powered software maximizes the revenues of large-scale energy storage and renewable assets on European short-term power markets—while minimizing risk. We're a 50+ person team that's fast-paced by nature, but the kind of place where people actually look out for each other. Following our successful Series A, we're investing in expanding our team – and we're excited to strengthen our team with new talent and continue growing together! Quick Check: Is this your Engineering Playground? Tech Stack: Python (Django/FastAPI), PostgreSQL/TimescaleDB, Redis, Celery, Docker, AWS, GitLab CI/CD, Sentry, Grafana
Your Focus: Support API and data projects, build and improve backend features, help connect real-time data and analytics, automate tasks, and contribute to both greenfield and legacy improvements
Team: Platform squad with Senior Engineers (API & Data focus), a Modelling expert, and direct CTO access—collaborative, async-friendly, pair programming, lots of mentoring
Product: Advanced energy trading & optimization platform, real-time APIs, data-driven, ML-integrated, high complexity
Who thrives here: Junior backend engineers eager to learn, contribute, and develop skills in both API and data/backend engineering
Must-haves: 1–3 years backend experience, solid Python skills, first experience with SQL databases, keen interest in APIs & data, willingness to learn new tools, collaborative mindset
Dealbreakers: No backend coding experience, no interest in both APIs and data, desire to work fully solo
Work closely with Senior Engineers to help design, build, and optimize backend features and APIs
Support the development and maintenance of databases, data pipelines, and real-time integrations
Participate in automating workflows and improving reliability, scalability, and security across the platform
Collaborate with data science, modelling, and product teams to deliver features for energy trading and analytics
Contribute ideas and improvements—whether for new greenfield projects or for optimizing legacy systems
Grow your skills through code reviews, pair programming, and regular feedback in a supportive team environment
1–3 years’ experience in backend development (Python, ideally with Django or FastAPI)
Hands-on experience with SQL databases (e.g. PostgreSQL) and an interest in data-driven products
Eager to learn API design, event-driven systems, and cloud tools (AWS, Docker, CI/CD etc.)
Collaborative, proactive, and open to feedback—ready to work in a team and learn from others
Good communication skills in English (B2); bonus if you have worked in international or cross-functional teams
Dealbreakers: No backend coding experience, no willingness to learn both API and data topics
People at the Core: Clear structures, democratic decisions, and a feedback culture where your voice counts.
Shape the Future: Contribute to the energy transition by working on sustainable energy solutions in a growing market environment.
Connecting & Co-Creating: Strategy off-sites and onsite weeks for real collaboration and shared ideas.
Work Your Way: Home office and flexible hours – you know what works best for you and your team.
Good Vibes: Yoga, shared lunches, after-work fun – we keep the energy up, even when it's busy.
Body & Mind: Urban Sports Club membership, wellbeing check-ins, and mental health support – your energy matters.
New Office: 10th-floor office with rooftop terrace, canteen, great views, ergonomic desks, hardware of your choice, and a pet-friendly environment.
Sustainable Extras: Deutschlandticket, FutureBens, and more – supporting your mobility and future.
We look forward to receiving your application, earliest start is as soon as possible. If you have any questions, feel free to reach out –  your contact is Kathi (Interim Talent Partner) . You’ll hear back from us  within 5 working days of your application . We value your time and want to make the process as transparent as possible. Once we receive your application, we’ll send you a confirmation email outlining the next steps and what you can expect from our interview process. We can’t wait to meet you! suena energy is an equal opportunity employer. We celebrate diversity and reject any form of discrimination. It is important to us to create an inclusive environment for all our team members. We want to particularly emphasize that our call for applicants is addressed to all genders. The integration of people with disabilities is an opportunity and not a problem for us, and we, therefore, welcome their application.