Senior Systems Engineer - Software

Software Engineering & Lifecycle Governance

• Software Acquisition & Governance: Monitor, identify, document, and report technical discrepancies across software acquisition planning, risk analyses, and acquisition strategy panels in compliance with AFI 99-103, AFSPCI 99-103, and SSC-S-001.
• Technical Audits & Reviews: Conduct technical evaluations during Functional and Physical Configuration Audits (FCA/PCA), Computer Resource Working Groups (CRWGs), specification reviews, and contractor proposal reviews.
• Software Assurance & Margin Analysis: Perform code, design, and data flow reviews, timing and memory margin analyses, performance predictions, and software capability assessments.

Spacecraft, Payload, & Ground Software Oversight

• Flight Software Subsystem (FSS) Oversight: Monitor spacecraft and payload flight software (FSW)-including Pointing and Control Assembly (PCA) FSW and Signal Processing Assembly (SPA) FSW-for GEO and HEO orbits.
• Ground Segment Integration: Evaluate ground software subsystems, including Tracking, Telemetry & Control (TT&C), Ground Control, Mission Management and Services, and crypto interface integrations.
• Obsolescence & Maintenance Analysis: Analyze hardware/software integration, databases, and flight/ground software code bases to resolve obsolescence issues and support onboard payload maintenance.
• Integration & Test (I&T) Verification: Review test plans, procedures, and simulation analyses to verify software functionality, system interoperability, and operational readiness.

• 7+ years of experience architecting, implementing, or integrating ground system components (satellite command & control, TT&C, data processing, communications, or mission planning).
• 7+ years of hands-on software engineering/development experience using C++, Python, or related technical stacks.
• 2+ years of leadership experience presenting or evaluating program lifecycle reviews (SRR, SDR, SFR, PDR, CDR, MRR, or TRR).
• 2+ years of experience developing or evaluating technical software design artifacts, Interface Control Documents (ICDs), and operational integration procedures.

Compliance & Standards

• Working knowledge of systems and software standards such as AFI 99-103, AFSPCI 99-103, or SSC-S-001.

Testing & Agile Methods

• Experience with system-level testing, hardware-in-the-loop debugging, and Agile software development workflows.

Education:

• Bachelor’s degree in a STEM discipline (Computer Science, Computer Engineering, Aerospace Engineering, Software Engineering, etc.).
• Clearance: Active TS Clearance.

What Desired Skills You’ll Bring:

• Full-Stack & Language Diversity: Proficiency in Java, C#, C, JavaScript, React, Node.js, or software automation frameworks.
• Specialized Software Standards: Knowledge of aviation or space software safety/quality standards (e.g., DO-178C, IEEE 12207).
• Space Systems Experience: Experience with NG OPIR, SBIRS, or Weather System Systems Engineering Plans (SEPs).
• Automated Testing & Workflow Optimization: Experience optimizing client workflows through automation tools and automated testing suites.
• Advanced Education: Master’s degree in Computer Science, Software Engineering, or related field.
• Clearance: Active Top Secret Clearance and ability to acquire SCI / SAP Access

$165,000.00 - $205,000.00 / yr 401(k) United States, California, El Segundo Jul 31, 2026 Modern Technology Solutions, Inc. (MTSI) is seeking a Software & Ground Systems Engineer to support nextgeneration space systems., The pay range for this position in California is $165,000/year to $205,000/year; however, base pay offered may vary depending on established government contract wages, job-related knowledge, skills, and experience, and other factors. MTSI also offers a full range of medical, financial, and other benefits, dependent on the position offered. Base pay information is based on market location. Applicants should apply via MTSI’s internal or external careers site. #LI-BH1 #mtsi #mtsijobs * Interesting Work: Our co-workers support some of the most important and critical programs to our national defense and security. * Values: Our first core value is that employees come first. We challenge our co-workers to provide the highest level of support and service, and reward them with some of the best benefits in the industry. * 100% Employee Owned: We have a stake in each other’s success, and the success of our customers. It’s also nice to know what’s going on across the company; we have company wide town-hall meetings three times a year. * Great Benefits - Most Full-Time Staff Are Eligible for:

* Starting PTO accrual of 20 days PTO/year + 10 holidays/year * Flexible schedules * 6% 401k match with immediate vesting up to $9k annually * Semi-annual bonus eligibility (July and December) * Company funded Employee Stock Ownership Plan (ESOP) - a separate qualified retirement account * Up to $10,000 in annual educational reimbursement * Other company funded benefits, like life and disability insurance * Optional zero deductible Blue Cross/Blue Shield health insurance plan

Track Record of Success: We have grown every year since our founding in 1993.

Modern Technology Solutions, Inc. (MTSI) is a 100% employee-owned engineering services and solutions company that provides high-demand technical expertise in Digital Transformation, Modeling and Simulation, Rapid Capability Development, Test and Evaluation, Artificial Intelligence, Autonomy, Cybersecurity and Mission Assurance

MTSI delivers capabilities to solve problems of global importance. Founded in 1993, MTSI today has employees at over 20 offices and field sites worldwide.