Principle Software Engineer C#

Leidos is seeking a Principal Software Engineer (C#) to work for the Security Enterprise Solutions (SES) business unit in Vista, CA. The SES business unit at Leidos designs and manufactures highly complex security equipment for use at border crossings, airports, seaports, and other transportation mechanisms. Our products include radiation detectors and spectrometers, X-ray and gamma ray scanners for cars, trucks and trains, and CT explosives detection equipment for airline passenger baggage. The ultimate goal for this position will be to update existing design as well as introduce new products to our already extensive line of security detection products. The products being developed through this effort are truly novel, and will make travel and trade safer, healthier, and more efficient on a global level.

The Principal Software Engineer (C#) will serve as a senior member of the technical team, providing technical leadership and expertise while fostering collaboration and team consensus. This individual will play a key role in driving innovation, enhancing security compliance, and mentoring other engineers. As part of a cross-functional team, the Principal Software Engineer will develop and maintain cargo inspection detection systems for the Ports and Borders group at Leidos. This role requires advanced technical expertise, a commitment to best practices, and a focus on delivering high-quality, secure software solutions.

Key Responsibilities :

Technical Contribution and Collaboration :

• Contribute to the design, development, testing, and maintenance of services, simulators, and diagnostics (WPF and Blazor) using C#.
• Provide technical leadership by guiding architectural decisions, fostering team collaboration, and ensuring alignment with best practices.
• Lead the adoption of tools, including AI-based software development tools, to enhance productivity and innovation.
• Promote team buy-in and shared ownership of technical solutions and processes.

Software Development and Security Compliance :

Problem Solving and Innovation :

Business Development Support :

Customer Interaction :

Project Estimation and Sustainability :

Communication and Reporting :

Required Skills :

Desired Skills :

Check out the links below to learn more about Security Enterprise Solutions (SES)

We’re not looking for perfectly polished resumes or perfect fits. We’re looking for people who break limits, ask hard questions, and don’t wait to be told what’s next. At Leidos, we’re not following the roadmap — we’re redrawing it.

Original Posting : November 4, 2025

For U.S. Positions : While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.

Pay Range :

Pay Range $126,100.00 - $227,950.00

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.