Software Tester jobs in Germany

We are looking for you as an addition to our tech-team in Berlin, Munich or Hamburg. 1KOMMA5° is building Germany's largest one-stop-shop for sale, installation and services related to solar, heat pumps, electricity and charging infrastructure. And they are all connected! Be a part of our mission!

Become a part of our mission and learn about our Product & Tech team!

At 1KOMMA5°, we connect and manage distributed energy devices at scale. As an IoT Platform Engineer, you will play a key role in developing and operating our 1K5 Heartbeat Gateway, the edge device that securely bridges thousands of energy assets with our cloud ecosystem.

You will work at the intersection of embedded systems, connectivity services, and hardware design, ensuring that our gateways are robust, updateable, and future-proof. Your contributions will directly shape the reliability, security, and scalability of the distributed energy network of tomorrow.

Key responsibilities include but are not limited to:

• Build and maintain the foundational software stack for our IoT gateway using Yocto-based Linux builds.
• Develop and optimize Go-based services for MQTT message brokering and integration with Eclipse Hono for telemetry and command flows.
• Implement logging and metrics collection pipelines to provide observability and troubleshooting capabilities for large-scale deployments.
• Implement and maintain secure OTA update pipelines using Mender, ensuring safe rollback and version management.
• Design and maintain secure boot and hardware safeguards to guarantee trusted firmware execution.
• Collaborate with hardware engineers on board-level design, validation, and certification of the gateway.
• Ensure compliance with security and connectivity certifications relevant to large-scale IoT deployments.

Technologies you will work with include:

• Go, Eclipse Hono, Mender, MQTT brokers, Secure Boot, Yocto
• Observability: Log collectors, metrics exporters, remote debugging tools
• DevOps: CI/CD pipelines, secure OTA processes

The successful candidate will have:

• Bachelor’s or Master’s degree in Computer Science, Electrical/Electronics Engineering, or related field.
• 5+ years of experience in IoT platform engineering.
• Proficiency in Go.
• Hands-on experience with OTA firmware deployment (Mender or equivalent).
• Previous involvement in low-level Linux kernel or driver customization.
• Solid understanding of MQTT, messaging backbones, and device-to-cloud data flows.
• Exposure to hardware design, validation, and certification processes.
• Familiarity with DevOps practices (CI/CD, containerization, test automation).
• Ability to collaborate across hardware, embedded, and cloud teams.
• Strong troubleshooting and analytical mindset.
• Clear and effective communicator in English (German is a plus).

Bonus points for:

• Experience with Eclipse Hono.
• Familiarity with Google Cloud Platform.
• Contributions to open-source projects related to MQTT, Yocto, or OTA update frameworks.
• Practical experience implementing secure boot
• Passion for climate tech and distributed energy systems.

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.

• You are part of a dynamic team with people who prove every day that they can make things happen and move companies forward with great positive impact
• You move in flat hierarchies and have short decision-making paths. You can learn a lot quickly and get involved at different levels
• You will be welcomed by a friendly and familiar team
• You are part of the energy transition and recognize in your daily work what purpose it serves
• You can work in one of our offices in Hamburg, Berlin or Munich
• You create a healthy balance alongside your work and enjoy all the benefits of the EGYM Wellpass
• Take advantage of benefits and discounts through 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