Payload Integration Engineer - Level 4

Sophia Space is a venture-backed deep technology company building high-performance, energy-efficient computing systems designed to operate in orbit. Our work sits at the intersection of aerospace systems, advanced computing, artificial intelligence, and applied physics, enabling a new generation of distributed edge computing capabilities in space.

Having successfully completed our Seed financing, Sophia is focused on scaling its team, products, and capabilities as we prepare for the next stage of growth. We are building a world-class engineering organization that combines expertise from aerospace, cloud computing, robotics, and AI to solve some of the most challenging problems in space infrastructure. As both a product company and an engineering-driven organization, we actively leverage modern AI tools throughout our development process to accelerate learning, improve productivity, and help deliver innovative, environmentally responsible computing platforms for the future.

Build the software that operates the payload on Sophia's first TILE demonstration mission, and carry that payload through integration, verification, and delivery to the spacecraft. The payload is an electro-optical imager. The software is a Linux application: it commands the imager, receives and timestamps its data, manages operating modes and faults, and hands the data to Sophia's onboard compute platform. You will write it, build the simulators and engineering testbed used to prove it, run the verification campaigns, and support checkout once the payload is on the spacecraft.

This is a software-led role with electrical and data-interface depth. Mechanical and thermal integration are covered by others; you coordinate with them rather than own that work. You will work closely with avionics, software, mission operations, the spacecraft integrator, and the payload vendor's firmware team, and you will be the person who understands the payload end to end.

Future missions expand into additional imaging modalities, science instruments, RF payloads, and optical communications terminals. The patterns you establish here become the template for those.

We use AI coding assistants where they help and expect you to as well.

This position is primarily in-person in Pasadena, California, with occasional hybrid flexibility based on business needs. Travel is light: expect about one trip to the spacecraft integrator.

Start as soon as possible. Contract-to-hire arrangements are welcome.

This position requires access to technology that is subject to U.S. export control laws. To comply with applicable ITAR and EAR regulations, applicants must qualify as a U.S. Person, as defined under those regulations. U.S. Persons generally include U.S. citizens, lawful permanent residents (green card holders), and certain protected individuals as defined by applicable law.

• First version against simulators. Stand up the payload control application and the simulators it talks to. Implement the command, telemetry, data, and timing interfaces from the interface documents, with tests.
• Engineering-unit campaign. Bring up the application against real hardware on the engineering testbed. Characterize the data path, timing, and fault behavior. Close out the interface documents against what the hardware actually does.
• Flight unit and delivery. Run the verification campaign on the flight unit, support environmental testing, and deliver the payload with its software, procedures, and test evidence to the spacecraft integrator.
• Checkout and commissioning. Support integration onto the spacecraft, pre-launch verification, and on-orbit payload commissioning.

• Design, build, and test the application that operates the payload: commanding, telemetry, data ingest, operating modes, timing, and fault handling.
• Implement the payload's software and data interfaces from interface documents, with tests that exercise the documented examples and edge cases.
• Work directly with the payload vendor's firmware team on boot sequences, command and telemetry protocols, frame timing, and fault behavior.
• Deploy and operate the application on Sophia's containerized onboard compute platform.

• Own the payload-to-bus interface control documents for software and data interfaces; coordinate with the mechanical and thermal owners on theirs.
• Define and verify the end-to-end data path from the payload sensor into Sophia's…