Junior Software Engineer - TS​/SCI Poly Security Clearance

Position: Junior Software Engineer - TS/SCI with Poly with Security Clearance
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- Description Leidos is seeking a motivated Junior Software Engineer to join our team in developing and maintaining modern web applications using React.js. This junior position is ideal for recent graduates or early-career professionals passionate about front-end development and eager to grow in a dynamic, mission-focused environment. You will work closely with experienced engineers in an Agile team, contributing to user-friendly interfaces while leveraging AI-powered tools to enhance productivity, code quality, and innovation.

This role provides hands-on experience with React.js and modern software practices, including the use of AI assistants (e.g., Git Hub Copilot, Cursor, Claude, or similar) to accelerate development tasks such as code generation, debugging, refactoring, and prompt engineering.

Primary Responsibilities:

* Develop and maintain user-facing features using React.js, including building reusable components and managing application state (e.g., use State, use Effect).

* Translate UI/UX designs and wireframes into high-quality, responsive code using HTML5, CSS3, and JavaScript (ES6+).

* Collaborate with backend developers to integrate RESTful APIs and ensure seamless data flow.

* Utilize AI coding tools (e.g., Git Hub Copilot, ChatGPT, Claude) for code suggestions, generation, debugging, refactoring, and optimization to improve development efficiency.

* Participate in code reviews, unit testing, and debugging to ensure performance, compatibility across browsers/devices, and adherence to best practices.

* Implement clean, modular, and maintainable code following team standards.

* Stay current with emerging front-end technologies and AI-assisted development trends.

* Contribute in an Agile environment, including daily stand-ups, sprint planning, and team collaboration.

Basic Qualifications:

* Bachelor's degree with 1+ years of experience. Additional experience may be considered in lieu of degree.

* US Citizen with an active TS/SCI with Poly security clearance

* Basic proficiency in JavaScript (ES6+), HTML5, and CSS
3.

* Fundamental knowledge of React.js (components, hooks, state management).

* Familiarity with version control tools such as Git.

* Experience or strong interest in AI tools for coding assistance (e.g., code generation, explanation, or optimization).

* Understanding of responsive design principles and basic web performance optimization.

* Strong problem-solving skills, eagerness to learn, and ability to work in a team environment.

* Excellent communication skills.

* CompTIA Security+ certification

Preferred Qualifications:

* Experience with modern build tools (e.g., npm/Yarn, Vite).

* Basic knowledge of Type Script or Redux.

* Exposure to RESTful APIs.

* Personal projects, bootcamp completion, or open-source contributions (Git Hub portfolio encouraged). Come break things (in a good way). Then build them smarter. We're the tech company everyone calls when things get weird. We don’t wear capes (they’re a safety hazard), but we do solve high-stakes problems with code, caffeine, and a healthy disregard for “how it’s always been done.” Original Posting:
December 30, 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 $57,850.00 - $ 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.

About Leidos Leidos is an industry and technology leader serving government and commercial customers with smarter, more efficient digital and mission innovations. Headquartered in Reston, Virginia, with 47,000 global employees, Leidos reported annual revenues of approximately $16.7 billion for the fiscal year ended January 3, 2025. For more…