Senior Software Engineer - Backend (m/f/d)

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. Want to be part of it?

We bring together regional craftsmanship and scalable software: We don't think of solar, batteries, heat pumps, and e-mobility as isolated components, but control them as an intelligent, integrated overall system in our virtual power plant. Directly connected to the electricity market – in real time, fully automated. This way, energy is used when it is available from renewables and particularly cost-effective. By 2030, our goal is to transition 1.5 million households to renewable energies. Over 3,000 people are working towards this every day, at more than 80 locations worldwide, from Finland to Australia.

Want to take responsibility and build solutions that truly matter? Apply now and help us shape the energy world of tomorrow.

Learn more about our Product & Tech team!

We are looking for a Senior Software Engineer - Backend with an interest in full stack development to join our Site Config team. You will help to design, build and shape the solutions that enable the seamless setup and configuration of our customers’ Home Energy Management Systems (HEMS). We are the layer between our IoT fleet and our customers and installers, and we are scaling fast - join us!

You will collaborate as part of our cross-functional team of frontend engineers, backend engineers, a product manager and a designer. Cloud Architects and SREs will enable you to easily deliver and run software in a consistent, secure and reliable way.
Our Stack: TypeScript, NestJS, NextJS, Flutter, GCP, Vercel, Cursor, Datadog
As a Senior Backend Engineer, you will:

• Plan, build and shape multiple business critical applications and integrations
• Thoughtfully create, implement, evaluate and deploy software solutions to solve complex problems in an elegant way
• Lay the foundation and architecture to scale globally
• Foster a culture of experiment-driven innovation within the team
• Promote teamwork and successful project execution
• Improve developer satisfaction by constantly avoiding/reducing tech-debt, automating as much as possible and documenting decisions, runbooks etc.
• Work across your boundaries and interact in close collaboration with our stakeholders and other teams

You check many of the following boxes:

• Proven experience in developing, shipping and monitoring scalable backend software solutions with TypeScript from several past projects
• Experience with NestJS in large scale applications is a clear plus - otherwise, experience with similar frameworks
• Able to communicate ideas clearly and concisely both in written and spoken form (our working language is English)
• You actively seek input from your peers and create visibility where it’s lacking
• A broad knowledge of architectural patterns and experience implementing them with modern devops best practices
• Worked in a cross-functional team being responsible for the full software development lifecycle, including leading project orchestration
• Interest in wearing different (metaphorical) hats: we expect our engineers to engage in product thinking and care deeply about business impact
• You feel comfortable with ambiguity and ask for what you need to get the job done
• You are excited to leverage AI tools to enhance your impact, including agentic coding

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 provide everyone with renewable energy technologies.
Bonus points for:

• Experience in Next.js or Flutter - We are experimenting with more fullstack roles, though you will remain primarily a backend expert
• Experience with CI/CD using GitHub Actions and cloud infrastructure (GCP/Vercel)
• A passion for the home energy and renewable sector