Senior Software Engineer (f/m/d)

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.

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.

• 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.

• 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 with software specialists, laser physicists, experimental experts, and systems-integration partners.

• You can move effectively between technical leadership, project coordination, architecture, and hands-on implementation.

• You take ownership of the quality, reliability, testability, and long-term maintainability of the systems you build.

• You communicate clearly with both software specialists and technical partners from adjacent disciplines.

• You apply sound technical judgment when making design, implementation, and technology-selection decisions in an evolving environment.

• You are curious, adaptable, and motivated to understand how software interacts with hardware, cameras, diagnostics, and experimental systems.

• You are experienced in debugging and testing complex software and understand their importance in senior-level engineering work.

• You value constructive feedback, knowledge sharing, and mentoring other engineers.

• You are interested in developing toward technical leadership and project ownership. Formal people-management responsibility is not required at the outset.

• Strong programming experience in C++, Python, or comparable programming languages.

• Experience designing, implementing, testing, debugging, and maintaining complex software systems.

• Knowledge of software architecture, code review practices, automated testing, technical documentation, and engineering best practices.

• Experience with greenfield development, platform or architecture definition, and making technology choices where requirements are still evolving.

• Experience with automated calibration, control-adjacent software, laboratory systems, automation, or physical-device interfaces.

• Experience developing human-machine interfaces, dashboards, or software for operating technical equipment.

• Experience with camera integration, image processing, diagnostic data, or experimental data-processing pipelines.

• Experience developing data-storage solutions for high-volume, time-series, experimental, or operational data.

• Familiarity with software-hardware integration and working across experimental-system boundaries.

• Experience with networked device communication or system interfaces, such as TCP/IP, REST APIs, webhooks, DDS, SCADA, or comparable technologies.

• Familiarity with control systems or optics is beneficial, but not required; the ability to learn and collaborate across these disciplines is more important.

• Previous experience mentoring engineers or leading technical design discussions.

• Innovative Technology & Mission: Be part of a cutting-edge company working on groundbreaking research in clean energy and scientific discovery.

• Career Development: We invest in our people. This is an opportunity to join an early, growing company at the forefront of new technology, where you’ll have the opportunity to develop and grow your career.

• Collaborative Culture: Work with great people in a dynamic, international environment with top-tier scientists, engineers and professionals passionate about solving global challenges.

• Ownership: Take ownership from day 1 and drive impact by making decisions, solving challenges and shaping the future of our company.

• Your Success is our Success: We offer a competitive salary and company ownership in the form of stock options, giving you a direct stake in our success and ownership in what we build together.

• Vacation Days: We support your work-life-balance by granting you 30 days of vacation per year.

• Snacks and Drinks: Our office fridges are never empty. Enjoy our healthy snacks and drinks. Our Darmstadt office even offers a canteen with delicious lunch options daily.

• Retirement Plan: If you decide for a private pension plan, we will finance 20% on top of your monthly contributions, plus loyalty incentives.

• Equipment: We offer state-of-the-art Windows or Apple Laptops. In addition, you will receive a keyboard, mouse and headset so you are fully equipped from day 1.

• Events: We organize regular events to foster team bonding, encourage collaboration, and build a strong, supportive company culture. Connect with colleagues across departments, share ideas, and have fun together, both in and outside of the workplace.

• Mobility with NAVIT: We partner with NAVIT to support your flexible commuting needs whether it’s a public transportation ticket, taxi rides or car-sharing you choose what fits your lifestyle.

• Fitness with Wellhub: We care about your health. Get access to a wide range of gyms, fitness studios and wellness services across Europe through our partnership with Wellhub.

Focused Energy is an equal opportunity employer committed to creating an inclusive environment. Qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender perception or identity, national origin, age, marital status, protected veteran status, or disability status.

Pursuant to the San Francisco Fair Chance Ordinance, Focused Energy will consider for employment qualified applicants with arrest and conviction records.

Compensation offered will be determined by factors such as location, level, job-related knowledge, skills, and experience. Certain roles may be eligible for incentive compensation, equity, benefits.