Principal Software Engineer - Test Systems

Engineers are the reason we exist—they’re the core of who we are. Embark on a journey with EXB Solutions at the forefront of technological innovation as we seek talented Engineers to shape the future of cutting-edge projects and contribute to a culture of excellence and creativity. What we do matters.

Quest Defense Systems & Solutions is seeking a Senior Principal, Principal, or Senior Software Engineer to support advanced aerospace and defense test systems. In this role, you’ll develop software, automation tools, and hardware interfaces that help validate mission-critical products in both engineering and production environments.

You’ll work hands-on with C++, C#, Python, Visual Studio, and lab instrumentation while partnering with cross-functional teams to solve integration challenges, troubleshoot complex systems, and keep high-visibility programs moving.

This is an excellent opportunity for a senior engineer who enjoys building software that interacts with real hardware, thrives in fast-paced environments, and wants to make a direct impact on cutting-edge defense technology.

Due to the nature of this role, all candidates must be U.S. citizens with the ability to obtain and maintain a Secret Clearance.

This role is onsite in Tucson, AZ. Relocation assistance is provided.

Key Responsibilities:

• Guiding multidisciplined teams in the development of test equipment

• Prioritize and handle multiple tasks in a production environment

• Contributing to cost and schedule management planning

• Communicating with senior management on project status

• Troubleshooting software and test equipment

• Develop requirements for software products

• Written and interpersonal communication skills with Program Management

Required Qualifications:

• Typically requires a bachelor’s degree in science, Technology, Engineering, or Mathematics (STEM) and minimum 5 years prior relevant experience, or an Advanced degree in a related field and minimum 3 years’ experience.  

• Minimum of 5 years developing and integrating software applications using programming languages including but not limited to C++. C#, Java, Python, or Visual Basic

• Minimum of 5 years of professional engineering experience utilizing integrated development environments and debugging tools to troubleshoot software implementation and ensure integrity of the software products.

• Experience with Windows Operating System and Microsoft Visual Studio, and Microsoft Azure DevOps Server.

• Familiarity with laboratory test instrumentation, electronics, and software (Ex. NI VISA, NI Measurement and Automation Explorer, NI Switch Executive)

Desired Qualifications:

• Working knowledge of computer architecture and computer hardware optimization techniques.

• Extensive knowledge of common computer hardware interface and data protocols such as TCP/IP, UDP, or RS-422

• Extensive knowledge of the development of software drivers for the operation of computer hardware interfaces.

• Professional experience with Unified Modeling Language (UML) to visualize software architecture and design (EX. IBM Rhapsody, Cameo System Modeler, and Cameo Enterprise Architecture)

• Professional experience of software development lifecycles, such as Agile

• Experience with Software Configuration Management principles

The QDSS Advantage:

At QDSS, our advantage is purpose-driven work, collaborative teams, and complex challenges that push boundaries and build lasting impact. You’ll grow your career while contributing to mission-critical programs that demand excellence and shape the future.

What You’ll Find Here

• Work That Matters – Next-generation, safety- and mission-critical projects where your contributions have real-world impact.

• Growth That’s Supported – Competitive compensation, employer-matched 401(k), certification assistance, and clear opportunities for advancement.

• A Culture That Works – A flexible, collaborative, and people-first environment where teamwork, innovation, and balance are valued.

Benefits Include

• Competitive pay, comprehensive medical/dental/life and disability coverage, 401(k) with employer match, professional development support, and a flexible, friendly workplace.

Full compensation package is based on candidate experience and certifications

Pay Ranges
$69—$74 USD

At Quest Defense Systems and Solutions, we don’t just build technology — we engineer the future. From next-generation aerospace solutions to cutting-edge defense systems, we tackle the toughest, mission-critical challenges that keep people safe and push the boundaries of innovation. This is where problem-solvers, innovators, and visionary thinkers come together to shape the future. With over 25 years of aerospace and defense engineering expertise, our commitment to delivering high-quality, transformative solutions sets us apart — not just as an industry leader, but as a driving force for impactful change. Together, we’re not just leading the industry — we’re revolutionizing it.

Quest Defense provides equal employment opportunities to all employees and applicants for employment and prohibits discrimination and harassment of any type without regard to race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state or local laws.

This policy applies to all terms and conditions of employment, including recruiting, hiring, placement, promotion, termination, layoff, recall, transfer, leaves of absence, compensation and training.The physical demands described here are representative of those that must be met by an employee to successfully perform the essential functions of this job. Reasonable accommodations may be made to enable individuals with disabilities to perform the essential functions.