Software Systems Engineer

Leidos is seeking a talented Software Systems Engineer to join a multi-disciplinary team within a matrixed organization to create unique solutions for complex problems, specifically regarding missile defense systems. With offices across the United States engaging in the defense, space, cyber and commercial fields, Leidos provides responsive, cost-effective engineering, scientific and IT solutions.

The Software Systems Engineer will support systems engineering needs throughout the software lifecycle of complex software systems. This includes deriving requirements, defining software interfaces and behaviors, and supporting verification and traceability of requirements. The selected candidate will develop and maintain a clear understanding of the overall software system functionality, interdependencies and interfaces. This includes communicating with a multi-disciplinary engineering team of both internal and external stakeholders. The selected candidate will also assist in maintaining the SysML software model in Cameo Systems Modeler.

Primary Responsibilities:

• Develop and maintain a clear understanding of overall system interdependencies and interfaces
• Derive software requirements and use cases with traceability to system requirements
• Drive definition of desired software functionality to meet System of System needs
• Utilize Model-Based Systems Engineering (MBSE) methodologies to support creation of deliverables and traceability to software requirements

Basic Qualifications

• A Bachelor’s degree in Systems Engineering, Software Engineering, Computer Science, Computer Engineering, or equivalent degree from an ABET-accredited university with 4-8 years of prior relevant experience or an MS with 2-6 years of prior relevant experience.
• Demonstrated understanding of the top-down systems engineering process for architecture development and bottoms-up verification
• Experience in deriving software requirements and use cases for complex systems
• Experience defining system interdependencies and interfaces
• Experience defining desired software functionality in collaboration with stakeholders
• Experience effectively collaborating and communicating within a multi-disciplinary team and external stakeholders
• Experience using requirement database tool(s) such as DOORS or Cameo Systems Modeler
• Experience working within an Agile environment (or equivalent)
• Must be a US Citizen and possess (and be able to maintain) a Final Secret Clearance or meet the eligibility to obtain (and maintain) a Secret Clearance

Preferred Qualifications

Preferred candidates will also have experience and/or working knowledge with:

• MBSE methodologies, particularly modeling in Cameo Systems Modeler (or equivalent) using SysML
• DoD acquisition processes and methods
• Software engineering throughout the software lifecycle
• Resident of the North Alabama area or willing to relocate to the Huntsville - North Alabama, AL area

If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.

Original Posting:

November 25, 2025

Pay Range:

Pay Range $85,150.00 - $153,925.00

The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.