<p>Leidos has a new and exciting opportunity for a Principal Software Engineer in our National Security Sector's (NSS) Cyber & Analytics Business Area (CABA). Our talented team is at the forefront in Security Engineering, Computer Network Operations (CNO), Mission Software, Analytical Methods and Modeling, Signals Intelligence (SIGINT), and Cryptographic Key Management. At Leidos, we offer competitive benefits, including Paid Time Off, 11 paid Holidays, 401K with a 6% company match and immediate vesting, Flexible Schedules, Discounted Stock Purchase Plans, Technical Upskilling, Education and Training Support, Parental Paid Leave, and much more. Join us and make a difference in National Security!</p> <p>This position is eligible for a sign on bonus of $25,000.</p> <p>Leidos is seeking a driven and experienced Full Stack Software Engineer to support a high-stakes, mission-critical program. In this role, you'll help architect, develop, and integrate software solutions that shape national security and drive meaningful innovation. Join an Agile team where your expertise won't just be valued-it will be vital.</p> <p>Primary Responsibilities</p> <ul> <li>Design, develop, and enhance secure software applications and systems </li><li>Integrate new software into evolving operational environments </li><li>Analyze user needs to craft efficient and scalable solutions </li><li>Debug and optimize existing software for performance and reliability </li><li>Implement complex algorithms that meet rigorous technical standards </li><li>Create and maintain system documentation and technical reports </li><li>Collaborate in Agile Scrum teams to deliver rapid, high-quality releases </li></ul> <p>Basic Qualifications</p> <ul> <li>Bachelor's degree in Computer Science or related discipline. In lieu of degree an additional 4 years of software engineering may be considered </li><li>20+ years of software engineering experience supporting programs of similar type and scope </li><li>Familiarity with front-end frameworks (React, Angular, or Vue) </li><li>Experience with modern programming languages such as Python </li><li>Clearance Requirement: Must have an active TS/SCI clearance with Polygraph </li></ul> <p>Desired Qualifications:</p> <ul> <li>React </li><li>Kibana </li><li>Elastic Search </li><li>Jupyter Notebook </li><li>Google Go </li><li>Java Script </li></ul> <p>CONMD</p> <p>CSSRC</p> <p>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.</p> <p>Original Posting:</p> <p>November 25, 2025</p> <p>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.</p> <p>Pay Range:</p> <p>Pay Range $154,050.00 - $278,475.00</p> <p>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.</p>