Principal Systems Engineer (T-04 level): Bachelor's Degree in STEM fields such as Computer Science, Systems Engineering, Mathematics, Physics, or a related discipline (e.g., human factors or psychology) from an accredited university is preferred, along with 8 years of experience; or a Master's degree in a STEM-related field with 6 years of relevant work experience; or a PhD in a related field with 4 years of relevant work experience. Principal Systems Engineer (T-03 level): Bachelor's Degree in STEM fields such as Computer Science, Systems Engineering, Mathematics, Physics, or a related discipline (e.g., human factors or psychology) from an accredited university is preferred, along with 5 years of experience; or a Master's degree in a STEM-related field with 3 years of relevant work experience; or a PhD in a related field with 1 year of relevant work experience.