Senior Fullstack Software Engineer - Ruby/ Typescript (m/f/d)

You will work on transforming the business of installing renewable technologies. With our core business software platform we streamline ground operations and rooftop installation to power the energy transition in private homes and small businesses world-wide.

As a software engineer in 1KOMMA5°, you will be part of a cross-functional team alongside frontend and backend engineers, product managers and UX/UI developers. You will help build a self-organized tech team, responsible for developing, deploying and running their own solutions to contribute to those work streams.

• Core Development: Develop and maintain the core Rails application with a focus on code health, modern patterns, and long-term stability
• ShapeUp Leadership: Lead technical implementation for complex projects within 6-week cycles, taking ownership from architectural design to shipping
• System Integration: Build pragmatic connections between the Rails monolith and satellite TypeScript/GCP services (Pub/Sub, Cloud Functions) without over-engineering
• Developer Experience: Proactively identify and resolve friction in tooling, CI/CD, and local environments to ensure the codebase remains enjoyable to work in
• Technical Standards: Drive high-quality async collaboration through clear documentation, architectural decision records (ADRs or RFCs), and comprehensive code reviews

With your work, you accelerate the "energy transition" and hence have a direct impact on our climate. By 2030, our goal is to transition 1.5 million households to renewable energies.

• proven experience in writing maintainable, self-describing, reusable and testable code with Rails and other major back-end or full-stack technologies in several past projects
• experience designing and maintaining RESTful APIs
• experience with measuring and improving performance
• an agile and result-oriented mindset and a passion to support your team colleagues
• interest or experience in human-centered software development
• excellent knowledge of spoken and written English, German is a plus
• residency in Germany
• We are an ambitious and dynamic company with a talented team. We require our engineers to be imaginative, enthusiastic, and willing to tackle new challenges as we strive to make an impact.

• You are part of an international, dynamic, and highly motivated team of people who have proven to make things happen
• With your work, you accelerate the "energy transition" and hence have a direct impact on our climate
• Work with and learn from other super-smart colleagues
• You will enjoy direct contact with core decision-makers
• You will enjoy the best chances of entering full-time in one of Europe’s most thriving scaleups
• You work remotely (Germany-wide), with offices in Hamburg, Berlin or Munich
• Create a healthy balance alongside your work and enjoy all the benefits of the EGYM Wellpass
• Benefits and discounts are yours with Futurebens
• Whether city bike or e-bike - be flexible with our job bike leasing and do something good for the environment at the same time

At 1KOMMA5°, we pursue a clear vision: Living on wind and sunlight forever for free. To make this a reality, we are building the energy system of the future with Heartbeat AI. We bring together regional craftsmanship and scalable software to control solar, batteries, heat pumps, and e-mobility as an intelligent, integrated overall system in our virtual power plant.