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Urban Sky is a venture-backed aerospace startup designing, building, and operating stratospheric balloon systems. The company sends flight vehicles to the stratosphere weekly, collecting data for applications ranging from wildfire monitoring to urban mapping. Urban Sky serves government customers including the Department of War, NASA, and others.
You will own HUSKY, the avionics bus and embedded Linux flight computer that powers every Urban Sky balloon. HUSKY's Go-based control plane reads vehicle sensors and batteries, controls payload and radio power, moves commands and telemetry between the vehicle and mission control over RF and satellite links, and provides operators with APIs and interfaces to run flights.
As Senior Firmware Engineer, you will be responsible for making HUSKY reliable, secure, and easy to evolve as the fleet grows and new payloads and customers come on board. Your ownership spans from hardware-level code to system architecture to build, test, and field deployment. You will define what next-generation revisions need, work with engineers to bring them up, and support defense customers integrating with the platform. This is a high-ownership role where your decisions directly affect flight safety and mission success every week.
Key responsibilities include: owning HUSKY flight software end-to-end as the technical lead; keeping vehicle hardware working through software (sensors, batteries, power distribution, GNSS, radios, mechanisms, payloads); making communications dependable over unreliable links with data that survives outages and reboots; designing for flight safety with fault detection, watchdogs, graceful degradation, and documented failure modes; owning how HUSKY is built, secured, and delivered to the fleet (CI/CD, release management, defense variants); building and maintaining test infrastructure; defining and documenting interfaces between HUSKY and microcontroller subsystems, payloads, and mission control; implementing security controls and supporting defense accreditation (encrypted communications, hardened configurations, secure boot, access control, STIG/RMF/ATO requirements); and serving as a technical point of contact for defense customers on integration, support, and network integration exercises.
You will be based at Urban Sky's Denver headquarters (4800 Race St) and expected to travel to support field campaigns, test flights, and customer integration.
QUALIFICATIONS:
- 5+ years of embedded software engineering with a track record of owning production software on Linux-based embedded devices
- Proficiency in Go plus strong systems programming fundamentals
- Experience developing on Linux SOM/SBC platforms (e.g., NXP i.MX, Toradex, Jetson, or similar) including board bring-up, device trees, kernel/driver configuration, and peripheral integration
- Experience with embedded Linux build environments such as Yocto and Buildroot, and shipping and updating containerized software on devices in the field
- Experience with Zephyr RTOS firmware on microcontrollers and defining interfaces between Linux and MCU subsystems
- Deep understanding of how software meets hardware on Linux
- Solid networking fundamentals (TCP/IP, RPC, serialization) and experience making systems reliable over intermittent, bandwidth-constrained links
- Experience defining system architecture and interfaces
- Comfortable owning a codebase end-to-end
- Hands-on with hardware and comfortable in the lab and field
- Clear technical communicator, credible with engineers and customers
- Must be US Citizen or Permanent Resident
- Ability to obtain and maintain a US security clearance may be required for certain programs
- Must be located near Denver, CO or willing to relocate
NICE-TO-HAVES:
- Nordic nRF / ARM Cortex-M microcontroller experience
- Aerospace, avionics, UAS, robotics, or satellite platform experience, including operation in extreme environments
- RF and satellite data link integration
- GNSS, IMU, or sensor integration experience
- Power systems and battery management experience
- Security hardening and DoD accreditation
- Model-based systems engineering (MBSE) or formal requirements traceability
