Freelance Junior Software Developer Jobs in Arizona

Immediately hiring engineers who want to contribute to mission-critical systems that demand precision, accountability, and technical excellence. Success here means solving real problems that keep complex systems moving forward.

Quest Defense Systems & Solutions is seeking a Software Engineer to join the Test Equipment Engineering (TEE) team. In this role, you will design, develop, integrate, and maintain Windows-based software applications that support the development, testing, and production of mission-critical weapon systems.

You will work closely with software, electrical, systems, and test engineers to create software solutions used in engineering laboratories, manufacturing environments, and production facilities. This position supports factory operations by developing applications, software libraries, and instrument drivers used with automated test equipment throughout the product lifecycle.

This is a hands-on software engineering role that combines application development, system integration, troubleshooting, and technical leadership.

This is a 100% onsite position based in Tucson, Arizona, where you'll enjoy the collaboration of working alongside your team every day. With more than 310 days of sunshine each year, stunning mountain views, and a vibrant yet relaxed lifestyle, Tucson offers an exceptional place to build both your career and your life.  All candidates must be U.S. citizens due to the nature of the work.  Clearance or the ability to obtain a clearance is strongly preferred unless otherwise stated below.

What You'll Do:

• Design, develop, test, and maintain Windows-based software applications using object-oriented programming principles.
• Develop software in C# and C++ using Microsoft Visual Studio.
• Create and maintain software libraries, utilities, and instrument drivers used with automated test equipment.
• Support software integration for engineering labs, manufacturing, and production test environments.
• Troubleshoot software issues and interface with automated test equipment and instrumentation.
• Work closely with cross-functional engineering teams, including Systems, Electrical, Mechanical, and Manufacturing Engineering.
• Develop software requirements and translate system requirements into software solutions.
• Support software throughout the engineering lifecycle, including development, verification, production, and sustainment.
• Manage multiple engineering tasks while balancing competing priorities.
• Lead technical efforts on software projects and provide guidance and mentorship to junior software engineers.
• Contribute to continuous improvements in software design, development practices, and test automation.

Required Qualifications

• Bachelor's degree in Computer Engineering, Computer Science, Software Engineering, Electrical Engineering, or another STEM-related field.
• 2-8 years of professional software engineering experience, or
• 5 years of professional software engineering experience with a Master's degree in a STEM discipline.
• Experience developing object-oriented software applications using:
  • C#
  • C++
• Experience using Microsoft Visual Studio.
• Experience developing software for Microsoft Windows operating systems.
• Experience designing, developing, debugging, and integrating software applications.
• Experience working in a collaborative, multidisciplinary engineering environment.
• Ability to manage multiple technical priorities simultaneously.
• U.S. Citizenship required.

Preferred Qualifications

• Experience developing software for automated test equipment (ATE).
• Experience creating software libraries and hardware instrument drivers.
• Experience in integrating software with electronic test instrumentation.
• Experience supporting manufacturing, production, or factory test environments.
• Experience developing software requirements and technical documentation.
• Experience supporting software throughout the full product development lifecycle.
• Experience troubleshooting integrated hardware and software systems.
• Previous experience mentoring or leading software engineers.
• Experience working within aerospace, defense, or other highly regulated engineering environments.
• Active U.S. Security Clearance.

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. 

This position may be filled at multiple levels depending on the candidate's experience and qualifications. Responsibilities and compensation will be aligned to the selected level.