Principal Full-Stack Engineer — Remote (Security Clearance)

X4 Life Sciences; Washington (District of Columbia, MD); Remote; USD 180,000 - 230,000; Full time

Benefits offered by this job

401(k)

Bonus

Remote with occasional in-person

Job summary

X4 Life Sciences seeks a Principal Full Stack Engineer to lead the design and delivery of secure, scalable web applications and AI-integrated systems for a government department. You will own architecture decisions across front-end, back-end, cloud, and AI layers, and guide the team toward robust security and performance.

The role is primarily remote with occasional in-person attendance in the Washington DC area; some interview rounds may be conducted on-site.

Qualifications

• 10+ years of professional software engineering experience, including full-stack work on customer-facing apps.
• Experience designing secure, scalable REST and GraphQL APIs.
• Hands-on cloud experience with AWS, Azure or GCP.
• Experience integrating AI/LLMs into production systems.
• Leadership in architecture direction and mentoring engineers.

Responsibilities

• Own the architecture of full-stack applications from front-end to back-end and cloud infra.
• Design, build and maintain scalable, secure web apps and APIs.
• Provision, manage and optimise cloud infrastructure, including government cloud environments where applicable.
• Design and implement integrations with LLMs and AI models, including autonomous agents.
• Set and uphold CI/CD pipelines and infrastructure-as-code standards.
• Mentor engineers, lead technical design reviews, and set code quality standards.
• Collaborate with product management to define requirements and deliver high-quality products.

Skills

Full-stack engineering

Python (FastAPI)

Node.js

REST APIs

GraphQL APIs

Cloud infrastructure

AWS/Azure/GCP

Databases (PostgreSQL/DynamoDB)

AI/LLM integration

Security & architecture leadership

CI/CD (GitHub Actions)

Mentorship

Tools

Terraform

Pulumi

AWS CDK

Job description

X4 Life Sciences seeks a Principal Full Stack Engineer to lead the design and delivery of secure, scalable web applications and AI-integrated systems for a government department. You will own architecture decisions across front-end, back-end, cloud, and AI layers, and guide the team toward robust security and performance.

The role is primarily remote with occasional in-person attendance in the Washington DC area; some interview rounds may be conducted on-site.