Mission-Critical Full-Stack Developer (TS/SCI)

Sphinx LLC; Springfield, Northern (VA, KY); Hybrid; USD 120,000 - 180,000; Full time

Job summary

Sphinx LLC is seeking a senior Full-Stack Software Developer to design, develop, and maintain mission-critical applications for internal teams and federal customers. You will work across front-end interfaces with React, Vite, and MUI, back-end services with Node/Express and PostgreSQL, and integrate shared tooling with TypeScript in both corporate and classified environments.

This role requires an active TS/SCI clearance with CI Poly, U.S.

Qualifications

• Active TS/SCI clearance with a current CI Polygraph (within the last 5 years)
• U.S. Citizenship (required for clearance eligibility)
• 8+ years of software development experience across the full stack
• AI-augmented development experience
• DevSecOps and CI/CD pipeline experience
• Secure coding experience (OWASP, NIST 800-53)

Responsibilities

• Design, develop, and maintain full-stack applications in corporate & classified environments
• Build responsive front ends (React, Vite, MUI), back-end services (Node, Express, PostgreSQL), and integrate shared tooling (TypeScript)
• Deploy and manage containerized applications
• Build and maintain DevSecOps and CI/CD pipelines for secure continuous delivery
• Apply secure coding practices aligned to OWASP guidelines and NIST 800-53 controls
• Architect and implement Zero Trust network and application design
• Partner with program security officers, data engineers, and mission stakeholders to translate requirements into working software

Skills

Full-stack development

AI-augmented development

DevSecOps

Secure coding

Zero Trust

CI/CD

Security standards

Education

BS in Computer Science or related field

Tools

React

Vite

MUI

Node

Express

PostgreSQL

TypeScript

Terraform

Ansible

Kubernetes

Job description

Sphinx LLC is seeking a senior Full-Stack Software Developer to design, develop, and maintain mission-critical applications for internal teams and federal customers. You will work across front-end interfaces with React, Vite, and MUI, back-end services with Node/Express and PostgreSQL, and integrate shared tooling with TypeScript in both corporate and classified environments.

This role requires an active TS/SCI clearance with CI Poly, U.S.