Senior Fullstack Developer Jobs in Chantilly, VA

Description:

About Millennial Software:

Millennial Software is revolutionizing the landscape of security and defense by leveraging our core competencies in software development, automation, DevSecOps, and machine learning.

• We are an employee-owned company, every employee receives equity in the company
• 100% company-paid medical, dental, and vision premiums for you and all dependents
• Ability to get increased salary if you don't need medical/dental/vision
• 100% company-paid disability and life insurance benefits
• 15% 401(k) company contribution
• 30 days of PTO/holidays
• Generous training budget
• Paid Paternal and Maternal Leave
• Business development / growth incentives
• Top notch company swag

About the Position:

Millennial Software is seeking a Junior-Mid Full Stack Software Developer to join our collaborative team supporting a Government customer. This is for a future contract slated to start in early 2027. You’ll contribute to the design, development, and support of modern, data-driven applications and tools that simplify complex user workflows and enable mission-critical decisions.

This is a great opportunity for a motivated developer to grow technical skills across the full stack, with a particular focus on modern software development processes and technologies.

The ideal candidate is passionate in the full lifecycle of application, including design, coding, testing, implementation, deployment as well as support and maintenance. The candidate must be comfortable collaborating closely with users and developers to build and maintain polished, high-performance tools in mission-critical environments.

Essential Functions:

• Design, build, test, and ship full-stack features spanning user interfaces, backend services, and data layers.
• Collaborate with product and design to translate requirements into technical plans and iterative deliverables.
• Build and maintain scalable APIs and service integrations; ensure correctness, reliability, and performance.
• Implement and maintain frontend components with attention to usability, responsiveness, and accessibility.
• Deploy, upgrade and maintain software components into Kubernetes based infrastructures using helm charts and command line tools.
• Write automated tests and participate in code reviews to maintain quality and reduce defects.
• Monitor, troubleshoot, and resolve production issues; participate in on-call or incident response as needed.
• Improve developer workflows (CI/CD, local dev, tooling) and system observability (logging, metrics, tracing).
• Document solutions, decisions, and operational runbooks to support long-term maintainability.
• Follow secure development practices and contribute to risk reduction (security, privacy, compliance as applicable).

Requirements:

Required Qualifications:

• Demonstrated experience delivering production software across both frontend and backend domains.
• Proficiency in at least one modern backend language (e.g., Python, Java, Go, C#, Node.js) and one modern frontend stack (e.g., JavaScript/TypeScript with React/Vue/Angular).
• Experience designing and consuming APIs (REST and/or GraphQL), integrating with databases, and handling data models.
• Experience with messaging and queuing platforms such as Kafka, RabbitMQ, or similar.
• Experience creating and maintaining Docker containers, Helm charts, orchestration platforms such as Kubernetes clusters, and using cloud infrastructure services (AWS/Azure/GCP).
• Working knowledge of software engineering fundamentals: version control, testing, debugging, performance, and secure coding.
• Experience collaborating in a team environment (code reviews, iterative delivery, clear communication).
• Ability to break down ambiguous problems and deliver solutions with measurable outcomes.
• Bachelor’s degree in a related field or equivalent practical experience.
• Willingness to be submitted for a TS/SCI clearance

Nice to have:

• Experience with event-driven systems (queues/streams), caching, and distributed system patterns.
• Familiarity with infrastructure-as-code and CI/CD best practices.
• Experience with observability tools (APM, structured logging, metrics, tracing).
• Exposure to accessibility standards (WCAG) and frontend performance optimization.
• Prior work in regulated environments or systems requiring strong security/compliance considerations.

Notice Regarding the Use of Artificial Intelligence in Application Review

Notice of AI Use in Job Application Review

As part of our commitment in creating a fair, efficient, and consistent hiring process we may use artificial intelligence (AI) to help our recruiting teams organize, summarize, and analyze information provided by candidates, including resumes, application responses, and other materials submitted during the application process.AI may be used to identify patterns, highlight relevant skills, and experience, and assist in comparing a candidate’s qualifications with the requirement of a specific role. These tools are to improve efficiency and consistency while supporting more informed hiring decisions, which will ultimately be made by the hiring team.