---
title: 'Principal Software Engineer at Focused'
canonical: 'https://feeny.ai/job/principal-software-engineer-focused-austin-hevekakaz0ys'
type: 'job'
last_seen: '2026-10-17'
---

# Principal Software Engineer at Focused

- **Company:** Focused
- **Location:** Austin, TX
- **Employment:** full-time
- **Work type:** hybrid
- **Posted:** 2026-09-21
- **Last confirmed live:** 2026-10-17
- **Apply:** https://jobs.ashbyhq.com/focused/b4846bf1-54df-408b-aa2a-5b1c7d581d5a

## Job description

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.

## Your Role

Focused Energy is looking for a Principal Software Engineer to define and own the Core Software architecture that will operate and integrate our fusion power plant. Sitting within the Software Department and reporting to the Head of Software, this is a foundational technical role: you will set the direction for how controls, hardware interfaces, calibration systems, data infrastructure, and human-machine interfaces come together into one coherent system. You will design and implement critical parts of the Core Software stack, stand up reliable automated calibration workflows, and set the engineering standards the rest of the department will build on. This is a rare opportunity to shape the software backbone of a fusion power plant and operate as a technical lead within the Software Department.

## What You'll Do

- Define and maintain the end-to-end Core Software architecture for the fusion power plant, including device interfaces, calibration, data handling, data storage, and HMI.
- Design and implement critical parts of the Core Software system using languages such as C++ and Python.
- Define clear interfaces between software, control hardware, diagnostics, plant equipment, data systems, and operator tools.
- Design reliable automated calibration facilities and workflows that produce traceable and repeatable results.
- Set practical standards for architecture, coding, testing, observability, documentation, release, reliability, security, and fault tolerance.
- Lead technical decisions across teams, mentor engineers, resolve difficult trade-offs, and grow into a lead within the Software Department.

## Who You Are

Must-Haves

- Extensive experience designing and implementing control software for complex physical or industrial systems.
- Extensive experience with hardware and software interfaces, including device integration and system-level troubleshooting.
- Experience designing and implementing automated calibration facilities or automated calibration workflows.
- Strong experience with data handling, data pipelines, metadata, and reliable data storage.
- Experience designing and implementing HMI for operators or technical users.
- Strong software design and implementation skills in C++, Python, or similar languages.
- Ability to define architecture for complex, mission-critical systems under changing requirements and strict physical constraints.
- Strong communication skills — you can explain technical decisions, risks, and trade-offs to software, hardware, science, and operations stakeholders.
- Strong leadership skills — you can guide decisions, mentor engineers, build alignment, and take ownership without relying on formal authority.
- Experience applying thorough testing, observability, reliability, fault tolerance, security, and documentation practices.

Nice-to-Haves

- Experience with software for plasma, nuclear power, high-energy physics, or scientific facilities.
- Experience with real-time or distributed control systems and high-throughput data acquisition.
- Experience defining shared frameworks, API conventions, configuration management, or communication systems for multiple teams.
- Experience writing architecture decision records or technical proposals and leading architecture reviews.
- Experience growing into a department-level technical lead or coaching senior engineers.
- Fluency with AI-assisted software development, or strong enthusiasm for using approved AI tools responsibly to improve quality and delivery.

## What We Offer

- 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.
- Medical, Dental, Vision: Multiple great plans to pick from that are active come the 1st Day of employment for you and any enrolled dependents.
- Vacation Days: We support your work-life-balance by granting you Unlimited PTO.
- Snacks and Drinks: Our office fridges are never empty. Enjoy our healthy snacks and drinks.
- Retirement Plan: If you decide to enroll in our 401k plan, we will match up to 4% on top of the employee contribution.
- 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.

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.

## About Focused

## Company Overview
- **One-liner**: Focused Energy is a laser-driven fusion company working to commercialize clean, limitless fusion power using technology proven at the National Ignition Facility (NIF).
- **Entity Type**: Private (Series A / Grant-funded)
- **Headquarters**: Darmstadt, Germany (global HQ) with major offices in San Francisco, CA, USA and Austin, TX, USA
- **Founded**: 2021
- **Founders**: Thomas Forner (CEO) and Prof. Dr. Markus Roth (CSO)

## Core Business
- Primary industry: Energy – nuclear fusion power generation
- Target customers: Utility companies, grid operators, governments
- Mission: To unleash the next chapter of economic growth and scientific innovation through the widespread adoption of clean, abundant fusion power.

## Products & Services
- **Laser-Driven Fusion Power Plant**: A commercial-scale fusion reactor designed to produce clean, limitless electricity. Currently in development with construction underway for an Integrated Test Facility and a Fusion Pilot Plant on a multi-stage Fusion Campus in Biblis, Germany.
- **Targetry & Laser Systems**: Proprietary fuel targets and high-power laser subsystems developed at the Darmstadt Targetry & Laser Laboratory (FELD) and the Austin Target Tracking & Engagement Facility.
- **R&D Collaborations**: Partnerships with U.S. national laboratories (LLNL, LLE) through the DOE INFUSE program, and with commercial partners such as Amplitude, ZEISS, and Fusioneering.

## Market Standing
- **Valuation**: Not disclosed
- **Key Metric**: Total funding of **$126.3M** (as of mid-2026), including a $50M grant from SPRIND, a $40M corporate round led by Amplitude Laser, an $11M Series A led by Prime Movers Lab, and ~$25M in additional grants from the U.S. DOE and German state governments.
- **Notable Investors/Partners**: Prime Movers Lab (lead investor), Amplitude Laser, SPRIND (German Federal Agency for Disruptive Innovation), U.S. Department of Energy, State of Hesse, Lawrence Livermore National Laboratory, University of Rochester Laboratory for Laser Energetics.
- **Growth Signals**: Headcount grew 73.6% year-over-year to 84 employees (LinkedIn, mid-2026); selected as one of eight companies for the DOE’s milestone-based fusion development program; new U.S. facility opened in Austin (2026); Fusion Campus in Biblis under construction.

## Competitive Advantages
- **Proven Science**: Approach builds directly on the NIF ignition breakthrough (2021); key team members (including CSO Dr. Debbie Callahan) were co-leaders of the NIF ignition campaign.
- **Deep Public Support**: Among the largest single public investments in laser fusion globally (~€70M from German federal and state sources combined).
- **Full-Stack Approach**: Controls targetry, lasers, and reactor design in-house, enabling rapid iteration and integration.
- **World-Class Team**: Over 150 scientists and engineers with deep expertise from major fusion labs, laser companies, and commercial energy startups.

## Strategic Focus
- **Build Fusion Campus**: Construction of a multi-stage facility in Biblis, Germany, housing an Integrated Test Facility, a Fusion Pilot Plant, and a first-of-its-kind commercial fusion power plant.
- **Scale Technology**: Validate engineering for commercial energy production through integrated prototype testing.
- **Expand U.S. Footprint**: Leverage Austin facility for target tracking, engagement systems, and program execution with U.S. partners.

## Why Work Here
- **Mission-Driven**: Directly contribute to solving the world’s energy and climate challenges with a technology that has already achieved scientific ignition.
- **World-Class R&D**: Collaborate with leading scientists from NIF, TU Darmstadt, and U.S. national labs in state-of-the-art laser and targetry labs.
- **Hybrid Options**: Many roles offer hybrid work arrangements; offices in Darmstadt, San Francisco, and Austin.
- **Culture**: Described as “relentless and brilliant” – a startup environment focused on engineering a step-change for civilization.
- **Growth Trajectory**: Rapidly expanding team and facilities; opportunities to shape a nascent industry.

## Sources
1. [Focused Energy Company Page](https://www.focused-energy.co/company)
2. [Focused Energy Careers Page](https://www.focused-energy.co/careers)
3. [LinkedIn Company Profile](https://www.linkedin.com/company/focused-energy-inc)
4. [Built In Company Profile](https://builtin.com/company/focused-energy-focused-energyco)
5. [Ashby Job Board](https://jobs.ashbyhq.com/focused)

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