Your Role

We're not just looking for someone who can write lines of code; we're seeking an individual who can think beyond code and question the "why" and "how" behind our software engineering processes while understanding the importance of our connection to our customers. As a Senior Firmware Engineer (m/f/d) at STABL Energy, you will drive innovation, solve complex challenges, and contribute to the success of our groundbreaking projects.

Your mission

• Design, implement, and test firmware for our cutting-edge power electronics products.
• Continue to implement new ways of assuring firmware quality.
• Collaborate with cross-functional teams to define project requirements and objectives, with a keen focus on meeting and exceeding customer expectations.
• Evaluate and optimize existing firmware code to enhance performance, reliability, and efficiency.
• Mentor and guide junior engineers, fostering a culture of continuous learning and improvement.
• Promote best practices in software engineering, emphasizing the importance of a holistic approach beyond just coding and its direct impact on customer satisfaction.

Your profile

• 4+ years of experience in firmware development for power electronics or other embedded systems.
• Comprehensive skills in the C programming language, in particular for embedded devices.
• Expertise on guiding firmware projects to professional standards.
• Strong problem-solving skills and the ability to think critically about software design and architecture.
• Proven ability to design and maintain robust firmware development ecosystems, including build infrastructure, modular frameworks, testing pipelines, and scalable release processes.
• Excellent English communication skills, with the ability to collaborate effectively with cross-functional teams and translate customer needs into technical solutions.
• You have interest and experience with a few of the following:
  • Real-time operating systems (RTOS).
  • Communication protocols such as SPI, UART, and CAN.
  • Microcontroller architectures.
  • Continuous integration (CI).
  • Testing strategies.
  • Product releases and versioning.
  • Build systems (e.g.make,CMake).

Why STABL Energy?

STABL Energy is one of the most innovative start-ups in the energy transition, ees Award winner 2022, pv magazine award winner 2025 and named a global Top100 Energy Start-up. We are funded by renowned and experienced Tech VCs from Germany, Denmark and Switzerland.

What you’ll love about working with us:

• Agile, open & innovation-driven culture with flat hierarchies, quick decision-making processes and real ownership
• Company pension scheme to support you plan for the future
• Flexible working hours, a hybrid work model, and the option to work remotely from abroad
• Digital meal vouchers with Circula Lunch - enjoy tasty lunches on us!
• Monthly benefit in kind to spend at your favourite stores
• Corporate benefits portal with exclusive employee discounts
• Regular team-building activities and team events
• Company EGYM Wellpass membership to train with no limits at numerous fitness clubs across Germany

Ready to innovate, impact, and inspire? Apply Now!

We’d love to hear from you to help us build the energy system of the future! Even if you don’t meet 100% of the requirements, we encourage you to apply anyway. Our motto is 'Hire for attitude, train for skills', so we value potential and lifelong learning just as much as experience.

About us

We make energy storage stable and secure the future of energy. As technological pioneers, we develop storage solutions that extend battery life cycles and encourage the sustainable use of resources. Our approach is simple: we never recycle a battery too soon. STABL Energy is more than just a traditional start-up company. Ready to be part of us, innovate, impact, and inspire?