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Millennial Software · 21 hours ago

Senior Frontend Software Engineer, TS/SCI with CI Poly - $180K-$210K + 15% 401k

Northern Virginia (Multiple Locations)

Full-time

Onsite

Senior Level, Lead/Staff

$180K/yr - $210K/yr

10+ years exp

Millennial Software is revolutionizing the landscape of security and defense by leveraging core competencies in software development, automation, DevSecOps, and machine learning. They are seeking a Senior Frontend Software Developer to design, develop, and support modern, data-driven applications and tools for a Government customer, focusing on enhancing user workflows and mission-critical decisions.

Application Performance ManagementCloud ComputingConsultingDeveloper ToolsDevOpsMobileQuality AssuranceSoftwareSoftware EngineeringWeb Development

No H1B

Security Clearance Required

U.S. Citizen Only

Responsibilities

Build and maintain web application features using modern frontend frameworks and best practices

Develop reusable UI components and patterns; contribute to a consistent design system

Ensure high-quality user experiences through responsiveness, accessibility, and performance optimization

Integrate with backend APIs and collaborate on API contract design to support feature delivery

Write and maintain automated tests (unit, component, and end-to-end where applicable)

Participate in code reviews and contribute to shared engineering standards and documentation

Debug and resolve frontend issues across browsers and devices; support production troubleshooting as needed

Improve frontend build, CI, and release processes; reduce friction for the engineering team

Qualification

JavaScript/TypeScriptModern frameworksHTML/CSSAPI integrationTesting practicesCollaboration with designAccessibility standardsDesign systemsSSR/SSG frameworksMicro-frontendsDocker containersCloud infrastructure

Required

Demonstrated experience building production web applications with modern JavaScript/TypeScript

Proficiency with at least one modern framework (e.g., React, Vue, Angular) and component-based design patterns

Strong understanding of HTML, CSS, browser fundamentals, and frontend performance considerations

Experience integrating with APIs and managing client-side state and data fetching patterns

Familiarity with testing practices (unit/component/E2E) and using Git-based workflows

Ability to partner effectively with design and product, translating requirements into polished UI

Bachelor's degree in a related field or equivalent practical experience

At least 10+ years of experience performing frontend software development

Active TS/SCI clearance

Ability to work on-site at one of the following locations - Virginia: Fairfax, Chantilly, McLean, Sterling or Colorado: Colorado Springs

Preferred

Experience with accessibility standards (WCAG), inclusive design, and usability testing practices

Familiarity with design systems, UI tooling, and collaboration workflows (e.g., Figma handoff patterns)

Experience with SSR/SSG frameworks (e.g., Next.js, Nuxt) and SEO/performance trade-offs

Experience with observability for frontend (client-side logging, performance monitoring, error tracking)

Experience with micro-frontends or large-scale frontend architecture

Knowledge of secure frontend practices (XSS prevention, CSP, secure auth flows)

Experience creating and maintaining Docker containers, Helm charts, orchestration platforms such as Kubernetes clusters, and using cloud infrastructure services (AWS/Azure/GCP)