Software Integration Engineer III/IV

Position Summary 

At Zone5 Technologies, we’re redefining what’s possible in unmanned aircraft systems. Our team of engineers and innovators is developing cutting-edge autonomous solutions that push the boundaries of UAS technology — solving complex challenges that matter. 

We’re building the future of UAS capabilities, and we’re looking for exceptional talent to join us. If you’re driven by hard problems, energized by rapid innovation, and ready to make an impact on next-generation flight systems, you belong here. 

The Software Integration Engineer III–IV is a senior individual contributor role responsible for owning system interfaces and integrating subsystems so they communicate reliably with one another. The engineer will integrate flight software, avionics, sensors, payloads, datalinks, ground systems, and vendor equipment; verify interfaces through laboratory, ground, and flight testing; and work closely with GNC, avionics, software, systems, and flight test teams to ensure safe and reliable aircraft performance. Engineers at this level are the technical authority for the interfaces they own. 

The ideal candidate combines: 

• Interface Control Documents (ICDs) & Interface Requirements 

• System & Subsystem Integration 

• Communication Protocols & Data Buses (Ethernet, Serial, CAN, MIL-STD-1553, ARINC 653, WOSA) 

• Messaging Middleware (DDS, ROS2, MAVLink) 

• Interface Verification & Validation (V&V) 

• Hardware-in-the-loop (HITL) & Software-in-the-loop (SITL) 

• Network & Bus Analysis 

• Systems Engineering & Requirements Management 

• Test Automation 

• Root Cause Analysis 

Level Expectations 

Level III (5+ years of experience) 

• Owns multiple subsystem interfaces end to end, from ICD definition through implementation, verification, and configuration control. 

• Authors and maintains ICDs and negotiates interface agreements with internal teams and external vendors. 

• Plans integration sequences and interface test campaigns and defines pass/fail criteria. 

• Leads root cause investigations for complex, cross-subsystem interface anomalies. 

• Provides technical guidance and peer review to junior engineers. 

Level IV (8+ years of experience) 

• Serves as interface authority for a full platform or across multiple platforms, owning the overall interface architecture and system data flow. 

• Defines interface standards, messaging architecture, and versioning and compatibility strategy used across products. 

• Leads integration of third-party, customer, and government-furnished systems and represents interfaces design reviews and customer engagements. 

• Resolves the most ambiguous, high-risk integration problems and mentors engineers at all levels. 

Responsibilities 

Interface Ownership 

• Own system and subsystem interfaces across flight software, avionics, sensors, payloads, datalinks, and ground control systems. 

• Collaborate with systems engineering to author, maintain, and configuration-control ICDs, interface requirements, message definitions, and data dictionaries. 

• Coordinate interface changes with internal teams, vendors, and customers. 

• Define interface architecture, including protocols, message sets, rates, timing, and error handling. 

• Assess the impact of proposed interface changes and manage versioning and backward compatibility. 

• Write software to integrate new components into Zone 5 systems and write software to integrate Zone 5 systems into existing platforms. 

Integration & Verification 

• Plan integration sequences and system build-up from component level through the full air vehicle. 

• Develop and execute interface and system-level integration and verification tests traceable to ICDs and requirements. 

• Develop simulators, emulators, and test harnesses for external systems. 

• Troubleshoot complex failures using bus and network captures, telemetry, logs, and system diagnostics. 

• Plan and support hardware-in-the-loop (HITL), software-in-the-loop (SITL), iron-bird, simulator, ground, and flight testing, serving as a representative from the software org to the test community at large. 

• Ensure test execution complies with safety requirements and test objectives. 

• Lead anomaly investigations, identify root causes, and drive corrective actions to closure. 

Technical Ownership & Collaboration 

• Coordinate software integration activities across multiple platforms. 

• Collaborate with multidisciplinary teams including software, systems, controls, guidance, avionics, and hardware engineers. 

• Design and improve automated interface testing, continuous integration, and HITL/SITL infrastructure. 

• Provide technical mentorship and code, ICD, and test reviews for junior engineers. 

• Integrate feedback from Test and Evaluation, and Production into procedures and test plans. 

• Represent interfaces and integration in design reviews, test readiness reviews, and customer engagements. 

• Support integration events, flight testing, field testing, and mission operations as needed. 

• Ensure compliance with applicable industry standards, safety requirements, and regulatory guidelines. 

• Research emerging technologies and recommend improvements to current integration activities. 

• Operate effectively in fast-paced prototype and development environments. 

Required Qualifications 

• Bachelor’s degree in Aerospace Engineering, Electrical Engineering, Mechanical Engineering, Systems Engineering, Computer Engineering, Computer Science, or a related technical field. 

• Level III: 5+ years of relevant experience in system integration, interface development, or V&V of aerospace, defense, or other safety-critical systems. 

• Level IV: 8+ years of relevant experience in system integration, interface development, or V&V of aerospace, defense, or other safety-critical systems. 

• Demonstrated experience authoring and owning ICDs and interface requirements. 

• Strong knowledge of communication protocols and data buses such as Ethernet (TCP/UDP), serial (RS-232/422/485), CAN, MIL-STD-1553, ARINC 653. 

• Experience integrating subsystems from multiple teams or vendors into a working system. 

• Understanding of aircraft systems and avionics integration. 

• Strong proficiency in one or more of the following: C/C++, Python, MATLAB/Simulink. 

• Hands-on experience with software-in-the-loop (SITL) and/or hardware-in-the-loop (HITL) test environments. 

• Experience with network and bus analysis tools such as Wireshark or CAN/1553 bus analyzers. 

• Proven track record of planning and executing integration campaigns from requirements through final report. 

• Strong analytical, problem-solving, and troubleshooting skills. 

• Excellent communication and teamwork skills, including negotiating interface agreements and briefing technical results to engineering leadership and customers. 

• Ability to obtain and maintain a U.S. security clearance. 

Preferred Qualifications 

• Experience with autonomous aircraft, UAVs, missiles, or robotic systems. 

• Familiarity with DDS, ROS2, MAVLink, STANAG 4586, or other UAS messaging standards. 

• Experience working with UAI (Universal Armaments Interface) and experience integrating, testing, or supporting mission stores on fixed-wing jet aircraft 

• Experience with military-grade GNSS receivers and navigational systems 

• Familiarity with open architecture standards such as WOSA. 

• Experience integrating datalinks, radios, and ground control systems. 

• Understanding of guidance, navigation, and control architectures. 

• Experience with time synchronization (e.g., PTP, IRIG-B, GPS time). 

• Familiarity with DO-178C, DO-160, and Model-Based Systems Engineering (MBSE), including SysML interface modeling. 

• Experience with flight-critical or safety-critical software. 

• Familiarity with VxWorks or other RTOS environments. 

• Experience with DevOps workflows and automated infrastructure. 

• Experience supporting flight tests or operational deployments. 

• Active U.S. security clearance. 

 Level III: $136,000 - $182,000/yr. 

Level IV: $164,000 - $210,000/yr.