Senior Full Stack Developer, TS​/SCI CI Poly

Senior Full Stack Developer, TS/SCI with CI Poly

$180K – $210K annually + 15% 401k

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

• Employee‑owned company with equity for all employees
• 100% company‑paid medical, dental, and vision premiums for you and all dependents
• Salary increase option for those who do not need medical/dental/vision premiums
• 100% company‑paid disability and life insurance benefits
• 15% 401(k) company contribution
• 30 days paid time off / holidays
• Paid paternal and maternal leave
• Generous training budget
• Business development / growth incentives
• Top‑notch company swag

Millennial Software is seeking a Senior Full Stack Software Developer to join our collaborative team supporting a Government customer. 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.

• 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).

• Demonstrated experience delivering production software across both frontend and backend domains.
• Proficiency in at least one modern backend language (Python, Java, Go, C#, Node.js) and one modern frontend stack (JavaScript/Type Script with React, Vue, or Angular).
• Experience designing and consuming APIs (REST and/or Graph
  
  QL), integrating with databases, and handling data models.
• Experience with messaging and queuing platforms such as Kafka, Rabbit
  
  MQ, or similar.
• Experience creating and maintaining Docker containers, Helm charts, 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.
• Active TS/SCI clearance.
• Ability to work on‑site in Virginia (Fairfax, Chantilly, McLean, Sterling) or Colorado (Colorado Springs).

• 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.

$180,000 – $210,000 annually

Mid‑Senior level

Full‑time

Engineering and Information Technology

Defense and Space Manufacturing

Millennial Software Solutions Inc. is an Equal Opportunity Employer and does not discriminate in employment on the basis of race, color, religion, sex, national origin, political affiliation, sexual orientation, gender identity, marital status, disability and genetic information, age, membership in an employee organization, or other non‑merit factor.