Staff Software Engineer, Defense Apps – Secret-Cleared

System One; Fort Belvoir (VA); On-site; USD 140,000 - 190,000; Full time

Job summary

System One IT is seeking two Staff Software Engineers to design and deliver mission-focused applications for a Department of Defense customer at Fort Belvoir, Virginia. You will own substantial software capabilities from architecture through production deployment, building user-facing apps, backend services, APIs, and data integrations.

The ideal candidate will have strong full stack experience, technical leadership, and hands-on work with Palantir Foundry or similar enterprise data platforms,

Qualifications

• Eight or more years of professional software engineering experience.
• Strong proficiency with JavaScript or TypeScript, React, and modern web application development.
• Experience developing backend services, APIs, and data-intensive applications.
• Experience building applications on Palantir Foundry or a comparable enterprise data platform.
• Demonstrated ownership of a significant software capability from architecture through production deployment.
• Experience supporting a Department of Defense customer.
• Active Secret clearance.

Responsibilities

• Own the architecture, development, and delivery of user-facing defense applications.
• Build responsive web interfaces, backend services, APIs, and data integrations.
• Develop applications using Palantir Foundry capabilities and modern web frameworks.
• Collaborate directly with Army users and product designers to understand operational workflows and refine application capabilities.
• Establish and promote effective engineering practices for architecture, testing, code review, security, CI/CD, and production operations.
• Diagnose and resolve complex application, data, and integration issues across the technology stack.
• Mentor engineers and contribute to technical decisions across the broader platform.
• Maintain high standards for software quality, reliability, security, and maintainability.

Skills

JavaScript/TypeScript

React

Web development

Backend services

APIs

Palantir Foundry

DoD experience

Secret clearance

Education

Bachelor’s degree in computer science or related field

Tools

Palantir Foundry

Job description

System One IT is seeking two Staff Software Engineers to design and deliver mission-focused applications for a Department of Defense customer at Fort Belvoir, Virginia. You will own substantial software capabilities from architecture through production deployment, building user-facing apps, backend services, APIs, and data integrations.

The ideal candidate will have strong full stack experience, technical leadership, and hands-on work with Palantir Foundry or similar enterprise data platforms,