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! At 1KOMMA5°, we connect and manage tens of thousands of distributed energy devices at scale. As a (Senior) Software Engineer - Device Connectivity, you will play a crucial role in integrating OEM devices, such as PV inverters, batteries, charging infrastructure, and heat pumps, into our cutting-edge Heartbeat platform. Your role involves implementing communication protocols, developing software modules on IoT gateway and controller devices, and conducting testing of our energy management system in our lab in Berlin. You will also be providing expert level support for both internal and external stakeholders. Collaborating with cross-functional teams, you'll contribute to the entire product lifecycle. Key responsibilities include but are not limited to: Own the technical integration of inverters, batteries, charging infrastructure, and heat pumps into our Heartbeat energy management system, driving projects end-to-end to deliver solutions on time. Ensure seamless communication and interoperability between different OEM devices. Implement communication protocols such as Modbus TCP, OCPP, MQTT, EEbus. Develop, deploy, and maintain services on our IoT gateway using Go programming. Diagnose network issues across LAN/WAN, VPN, firewalls, and protocols, and turn that understanding into resilient edge services. Conduct testing of our energy management system in our lab in Berlin. Collaborate with cross-functional teams to ensure software meets performance and reliability standards. Provide expert-level support to both internal and external stakeholders. Foster a culture of experiment-driven innovation within the team Bachelor's or Master's degree in Computer Science, Electrical/Electronics Engineering, Control Engineering or related field. Proven experience in IoT development and integration, with a focus on integrating diverse OEM devices. Hands-on experience in the development of software modules for IoT devices. Experience with Go programming is highly preferred. Proficiency in communication protocols such as Modbus TCP, OCPP, and MQTT. Solid understanding of local area networks (TCP/IP, LAN/WLAN) and experience with device discovery and scanning mechanisms within home networks. Familiarity with DevOps practices and tools, including continuous integration and deployment (CI/CD) pipelines. Prior exposure to energy management systems is desirable. Outstanding, proactive communication skills: you excel at engaging stakeholders and initiating cross-team collaboration Excellent troubleshooting and problem-solving skills. Experience quickly finding your way around in cross-functional teams in a fast pace, interdisciplinary working environment An agile and result-oriented mindset and you consider yourself a team player Very good knowledge of spoken and written English, German is a plus Bonus points for: Experience in network or systems administration (routing, firewalls, DNS, DHCP) in a production environment. Familiarity with cloud platforms (ideally Google cloud) and their integration in IoT solutions. Previous experience in providing support to international stakeholders. Certifications related to IoT and energy management 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.