Freelance Digital Hardware Design Engineer Jobs in Arizona

At QDSS, we focus on solving complex problems that directly impact production, quality, and system performance.

If you thrive in hands-on, technical environments, you'll feel right at home here.

Quest Defense Systems & Solutions is seeking multiple Digital Design Engineers across mid-level through senior-level experience levels to support the design and development of advanced digital electronics for missile and defense applications. These engineers will work on complex electronic hardware used in missile guidance, video processing, digital signal processing, and other mission-critical systems.

In this role, you will contribute throughout the full digital hardware development lifecycle, from requirements and architecture through schematic design, analysis, simulation, hardware checkout, test, and integration.

The ideal candidate has hands-on experience designing circuit card assemblies (CCAs) incorporating processors, FPGAs, memory devices, and high-speed digital interfaces. Opportunities are available for engineers with approximately 2+ through 8+ years of relevant experience, with responsibilities and technical leadership increasing based on level.

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 US 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 Will Be Doing

• Design, develop, analyze, simulate, test, and integrate digital electronic modules and complex circuit card assemblies (CCAs)
• Translate system and hardware requirements into detailed digital hardware architectures and designs
• Develop hardware architecture including block diagrams, interfaces, and design concepts
• Perform schematic capture and collaborate closely with PCB layout engineers throughout the physical design process
• Select processors, FPGAs, memory devices, interface components, and other electronic parts
• Conduct component evaluations, parts selection, and technical trade studies
• Design hardware incorporating digital interfaces such as PCIe, Ethernet, I2C, SPI, and UART
• Support complex, multi-layer PCB/CCA development and apply appropriate electrical and physical design constraints
• Perform design analysis and simulation prior to hardware fabrication
• Support signal and power integrity analysis as appropriate to the design
• Develop test plans and procedures for hardware verification
• Perform laboratory checkout, troubleshooting, debugging, and integration using standard electronic test equipment
• Collaborate with FPGA, software, systems, mechanical, manufacturing, test, and other engineering disciplines
• Support designs through development, integration, qualification, and transition into production

Required Qualifications: 

Digital Design Engineer II - Approximately 2+ Years

• Bachelor's degree in Electrical Engineering, Computer Engineering, or a related engineering discipline
• 2+ years of relevant digital electronics, hardware design, or circuit card development experience
• Experience with digital circuit design, analysis, simulation, or testing
• Understanding of schematic design and PCB/CCA development processes
• Experience working with processors, FPGAs, memory, or digital communication interfaces
• Hands-on laboratory experience using electronic test and measurement equipment
• Ability to work collaboratively within a multidisciplinary engineering team

Digital Design Engineer III - Approximately 5+ Years

In addition to the qualifications above:

• 5+ years of experience developing and designing electronic circuits, CCAs, or multi-assembly electronic systems
• Experience developing and supporting complex, multi-layer circuit card assemblies
• Proficiency with electronic design and simulation tools used for schematic development, PCB design support, and hardware analysis
• Experience with requirements analysis, parts selection, trade studies, hardware architecture, and schematic capture
• Experience supporting PCB physical layout and applying appropriate design constraints
• Ability to independently support hardware checkout, troubleshooting, and integration

Digital Design Engineer IV - Approximately 8+ Years

In addition to the qualifications above:

• 8+ years of experience developing digital electronics, circuit card assemblies, and/or multi-assembly electronic systems
• Demonstrated ability to take a hardware design from requirements or initial block-diagram concept through detailed design, hardware fabrication, test, and integration
• Strong understanding of the complete PCB/CCA design process
• Advanced experience with schematic capture, design analysis, simulation, and design verification prior to hardware execution
• Experience developing complex hardware incorporating processors, FPGAs, memory, and high-speed digital interfaces
• Strong background developing multi-layer CCAs and defining or applying hardware design constraints
• Ability to provide technical direction, mentor less-experienced engineers, and lead hardware development activities
• Experience supporting programs through development and transition into production

Preferred Skills: 

• Experience designing electronics for missile, aerospace, avionics, defense, or other high-reliability applications
• Experience with high-speed digital electronics
• Experience with homogeneous or heterogeneous multiprocessor architectures
• Familiarity with FPGA development and integration
• Familiarity with embedded software and hardware/software integration
• Experience with signal integrity and/or power integrity analysis
• Experience troubleshooting prototype hardware in a laboratory environment
• Experience supporting hardware throughout the complete product development lifecycle
• Previous experience developing electronics within regulated, mission-critical, or safety-critical environments

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.

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.