Senior Software Engineer, Operating Systems

Spacecraft represent the most pressing unmet need across the entire aerospace industry. As more launch vehicles come online and the cost to orbit decreases, more companies launching payloads to space continue to emerge.

For the first time in history, this influx of payload companies combined with reduced launch costs has resulted in a massive increase in need for commercial spacecraft platforms, known as satellite buses. These buses hold the payloads of our customers and are flown on launch vehicles.

Apex manufactures these satellite buses at scale using a combination of software, vertical integration, and hardware that is designed for manufacturing. Our spacecraft enable the future of society: ranging from earth observation to communications and more.

We’d love for you to join us on our mission of providing humankind access to the galaxy beyond our planet.

As a Senior Operating Systems Engineer on Apex's Flight Software team, you will design, develop, and own the software that brings our spacecraft to life. You will tackle the hardest problems in autonomous systems and build robust software that enables reliable spacecraft operation 24/7, across every phase of a mission. You will work closely with our mission operations, GNC, and hardware teams to architect new systems, prototype ideas, and turn them into mission-critical software that ultimately flies.

Experience in the space industry is not necessary to thrive tead, we are looking for motivated engineers who enjoy solving complex problems, balance technical rigor with practicality, and thrive in a dynamic, fast-paced environment.

The Flight Software team is composed of three interconnected teams: high-level application software, operating system software, and embedded software. There is significant collaboration and crossover across these teams.

• Develop the low level software that configures and drives the processor peripherals and communication interfaces on our avionics.

• Develop, configure, and maintain embedded Linux platforms and boot loader frameworks, including Yocto, Buildroot, Wolf Boot, and U-Boot.

• Design, implement, and validate firmware update mechanisms, including boot loader integration, secure firmware deployment, and recovery procedures.

• Design and implement security enhancements across complex software architectures to improve system integrity, resilience, and secure operation.

• U.S. Person status is required as this position needs to access export controlled data.

• Bachelor's degree in CS, EE or equivalent, or equivalent professional experience.

• 8+ years writing code for operating systems, ideally Yocto or embedded Linux on spacecraft, robotics, automotive, or other hardware what that interacts with the physical world

• Strong proficiency in programming languages such as Python, C++, or Rust

• Experience developing, testing, deploying, and troubleshooting mission-critical satellite software from prototyping through flight operations.

• Experience with embedded Linux platforms and boot loader frameworks (e.g., Yocto, Buildroot, Wolf Boot, U-Boot).

• Experience bringing up new avionics and flight hardware from initial power-on through functional verification.

• Experience with hardware/software integration, schematic analysis, and hardware debugging using oscilloscopes and logic analyzers.

• Familiarity with spacecraft attitude control systems, including reaction wheels, magnetorquers, thrusters, and associated sensors.

• Experience designing, implementing, and validating firmware update mechanisms, including boot loader integration, secure firmware deployment, and update recovery.

• Experience designing secure systems and implementing security enhancements in complex software architectures.

Pay Range:
Senior: $185K - $210K
Staff: $200K - $250K

Apex believes in creating a work environment that you look forward to embracing every day. Our employees love working at Apex, and we want you to love it too. We're a fast-growing startup that has raised more than $500M in funding, and we invest heavily in our people from day one.

• Shared upside: Receive equity in Apex, letting you benefit from the work you create

• Best-in-class healthcare: 100% company-paid medical, dental, and vision for you and your dependents, plus $100k life insurance at no cost

• Comprehensive PTO package: Starting at 15 days vacation, growing to 20+ days annually, plus 10 paid holidays

• Competitive 401(k) plan: Generous…