Principal Test Engineer

Job Description Mercury Systems is seeking the best and brightest talent to help us bring cutting-edge technology to mission-critical aerospace and defense applications, advancing innovation where it matters most. Our Mixed Signal business unit is seeking an experienced Principal Test Engineer to develop and execute comprehensive test strategies for sophisticated mission-critical embedded technology designed to withstand the most rugged environments. This role requires deep expertise in digital hardware testing, ASIC/FPGA verification, and environmental qualification testing for aerospace and defense applications.

You will own the complete test lifecycle from Design Verification Testing (DVT) through production test deployment, including test automation software development, test fixture design, and formal qualification documentation.

This is an ideal opportunity for someone who thinks like a design engineer but lives in the test world—someone who can build test infrastructure as a product in its own right with the same rigor applied to flight hardware.

Job Responsibilities:

Develop and execute Design Verification Test (DVT) plans and procedures for complex digital circuits, modules, and systems including ASIC integration and FPGA verification

Design, build, and certify test fixtures, cable harnesses, and test interface boards for complex digital subsystems

Develop automated test systems using modern programming languages (Python, .NET) including instrument control, data acquisition, and automated pass/fail determination;
LabVIEW support for existing systems

Develop test firmware for embedded targets including SPI/I2C/UART communication protocols and diagnostic interfaces

Execute environmental and qualification testing per MIL-STD-810H (thermal, vibration, shock, acceleration) and MIL-STD-461G (EMI/EMC) standards

Perform ASIC integration testing including register read/write verification, state machine validation, and high-speed SPI interface testing

Test high-speed digital interfaces including PCIe, Ethernet, DDR SDRAM, and complex power sequencing circuits

Conduct burn-in testing, accelerated life testing, and reliability qualification campaigns

Perform root cause analysis on test failures with first-responder anomaly triage and failure mode characterization

Develop comprehensive test plans, test procedures, and formal test reports traceable to product requirements (JAMA, DOORS)
Maintain test assets under configuration management with NIST-traceable calibration records

Prepare and present Test Readiness Review (TRR) packages for qualification events

Lead production test handoff activities including manufacturing test documentation and knowledge transfer

Interface with design engineering, program management, manufacturing, and customers to resolve technical test issues

Required Qualifications:

Bachelor's degree in Electrical Engineering, Computer Engineering, or related field

Typically requires 6+ years of related experience in electronics test engineering

Hands-on experience testing complex digital subsystems including FPGA verification and ASIC integration

Experience programming skills in Python and/or .NET for test automation, data analysis, and embedded test firmware development

Experience with test firmware development for embedded systems including SPI, I2C, UART protocol implementations

Experience executing MIL-STD-810H and MIL-STD-461G qualification testing campaigns

Experience with RF and digital test equipment including: spectrum analyzers, network analyzers (VNA), signal generators, oscilloscopes, logic analyzers, power supplies, and thermal chambers.

This position requires you to have or obtain a government security clearance. Security clearances may only be granted to U.S. citizens.

Preferred Qualifications:

Master's degree in Electrical Engineering Active Secret clearance or higher

Experience with ruggedized military and space-grade electronics testing

Experience with AI-assisted development tools (Claude Code, Cursor, Git Hub Copilot, or similar) for accelerating test automation development

Demonstrated ability to leverage modern development workflows and AI coding assistants

Proficiency in C/C++, Rust, VHDL, MATLAB, and/or SQL for specialized test applications and data management

Experience with radiation qualification testing at external facilities

Knowledge of high-speed digital design including signal integrity and power integrity analysis

Experience testing Intel (Xilinx) and AMD (Altera) FPGA-based systems

Familiarity with…