Senior Software Engineer (f/m/d)

About Focused Energy Focused Energy is building the future of clean energy through laser-driven inertial fusion. Backed by our $240M Series A - the largest fully secured Series A in the global fusion industry we are scaling rapidly across multiple geographies. Based in Germany and the US, we have brought together the top scientific and engineering minds using proven technologies to unlock fusion power at commercial scale. Focused Energy is working to realize game-changing scientific innovation that promises to deliver a clean, sustainable and abundant source of power globally. About the Role As a Senior Software Engineer, you will be the primary software point of contact for the Laser team and provide technical leadership across software, hardware, and experimental-system interfaces. You will help define the architecture and technology direction for a greenfield laser-software platform while remaining hands-on in developing reliable tools for calibration, operation, human-machine interaction, and experimental data processing. This role offers the opportunity to work across software, hardware, and experimental-system boundaries while contributing to a strong engineering culture within the Darmstadt Software Department. You will help shape technical direction, establish the foundations of a new software platform, and grow toward a broader technical leadership role. The position does not initially include direct people-management responsibility. What You’ll Do • Act as the primary software partner for the Laser team and coordinate software activities across laser projects. • Provide technical leadership for software initiatives, including planning, technical alignment, risk identification, and coordination with laser physicists, engineers, and systems-integration partners. • Help define the architecture, technology choices, development practices, and interfaces for a new laser-software platform in a greenfield environment. • Design and implement reliable software for critical laser projects, from system-level interfaces to user-facing applications. • Develop and maintain automated calibration software that improves repeatability, reduces manual effort, and supports reliable laser operation. • Design and build clear, dependable human-machine interfaces, dashboards, and operational tools for monitoring and operating laser systems. • Develop software that interfaces with laser devices, diagnostic systems, cameras, and experimental equipment to support data acquisition, system monitoring, operational control, and visualization. • Develop data-processing pipelines and data-storage solutions for experimental and operational data, including diagnostic and camera data where appropriate. • Define robust interfaces between software, hardware, cameras, and experimental systems in an environment where requirements and technologies are still evolving. • Work with networked device and system interfaces, potentially including TCP/IP, REST APIs, webhooks, DDS, SCADA, or comparable communication technologies. • Write automated tests, technical documentation, and operational guidance to support long-term maintainability and safe, reliable operation. • Identify and address reliability, performance, integration, debugging, and maintenance risks in software that interacts with real-world systems. • Contribute to technical design discussions, code reviews, and knowledge sharing across the Software Department. • Mentor engineers and help establish engineering practices as the software team grows. Who You Are • You are an experienced software engineer who enjoys solving complex, ambiguous technical problems and building systems from the ground up. • You are comfortable taking ownership of technical direction while collaborating closely wi