Junior Fastapi Developer Jobs in Colorado (NOW HIRING)

Job Title: Mid-Senior Full Stack Developer
Job Category: Engineering
Time Type: Full time
Minimum Clearance Required to Start: TS/SCI with Polygraph
Employee Type: Regular
Percentage of Travel Required: Up to 10%
Type of Travel: Continental US
Anticipated Posting End: 8/31/2026
The Opportunity:
As part of the Clairvoyant program, you will design and build the primary touchpoint between our platform and its customers - a sophisticated API layer and modern web UI delivering critical, real-time data to third-party partners.
As a Mid-Senior Full Stack Developer, you will operate within a hardened, AWS-based, Kubernetes-native environment where modern interface standards meet strict government security requirements. This is a high-visibility role where you will:

• Engineer the Interface: Build responsive web applications using React that visualize complex, real-time data sets for external customers.
• Architect the API Layer: Design and maintain RESTful or GraphQL APIs supporting seamless third-party integrations at scale.
• Secure the Stack: Implement OAuth2, OIDC, and mTLS protocols and ensure all code meets DISA STIG and OWASP standards.
• Own the Lifecycle: Drive the full SDLC from agile requirements through automated CI/CD deployment on Kubernetes.

Responsibilities:

• Design and maintain responsive front-end applications using React, handling complex data visualization and high-concurrency use cases for external partners.
• Build and maintain scalable RESTful and GraphQL APIs using Node.js, Python (FastAPI/Flask), or Java (Spring Boot) for third-party data access.
• Implement authentication and authorization patterns including OAuth2, OIDC, mTLS, and RBAC to ensure secure external data access.
• Design and optimize relational (PostgreSQL) and non-relational (Elasticsearch, Redis) data store interactions.
• Containerize applications with Docker and deploy to Kubernetes on AWS in coordination with the DevSecOps team.
• Ensure all code meets DISA STIG requirements and addresses the OWASP Top 10 throughout the development lifecycle.
• Integrate with GitLab CI/CD pipelines and Helm charts for deployment across environments.
• Conduct code reviews, provide technical guidance for junior developers, and serve as the SME for third-party API integration.
• Maintain technical documentation, API specifications, and integration guides.

Qualifications:
Required:

• Current TS/SCI clearance with Polygraph.
• Bachelor's degree in Computer Science or related field, or equivalent experience.
• 5+ years (mid-level) or 10+ years (senior-level) of full-stack software engineering experience.
• Advanced proficiency in JavaScript/TypeScript and React, including Redux and Context API.
• Strong experience building APIs with Node.js, Python (FastAPI/Flask), or Java (Spring Boot).
• Proficiency with Docker - writing Dockerfiles, building hardened images, and integrating with CI/CD pipelines.
• Familiarity with GitLab CI/CD, Helm, and Kubernetes deployment.
• Comfortable working in an agile, distributed team environment.
• Ability to travel up to 5%.

Desired:

• Experience with data visualization libraries such as D3.js or Recharts.
• Familiarity with GraphQL federation and advanced API design patterns.
• Experience with AWS services including ECS/EKS, API Gateway, CloudFront, and RDS.
• Working knowledge of OAuth2, OIDC, mTLS, and modern API security patterns.
• Knowledge of the OWASP Top 10 and STIG-compliant development practices.
• Exposure to Elasticsearch query optimization and index management at scale.
• Working knowledge of OAuth2, OIDC, mTLS, and modern API security patterns.
• Knowledge of the OWASP Top 10 and STIG-compliant development practices.
• Familiarity with RHEL 9 hardening and STIG compliance at the OS and container level.
• Relevant certifications: AWS Developer Associate, CKAD, or CompTIA Security+.

What You Can Expect:
A culture of integrity.
At CACI, we place character and innovation at the center of everything we do. As a valued team member, you'll be part of a high-performing group dedicated to our customer's missions and driven by a higher purpose - to ensure the safety of our nation.
An environment of trust.
CACI values the unique contributions that every employee brings to our company and our customers - every day. You'll have the autonomy to take the time you need through a unique flexible time off benefit and have access to robust learning resources to make your ambitions a reality.
A focus on continuous growth.
Together, we will advance our nation's most critical missions, build on our lengthy track record of business success, and find opportunities to break new ground - in your career and in our legacy.
Pay Range:
There are a host of factors that can influence final salary including, but not limited to, geographic location, Federal Government contract labor categories and contract wage rates, relevant prior work experience, specific skills and competencies, education, and certifications. Our employees value the flexibility at CACI that allows them to balance quality work and their personal lives. We offer competitive compensation, benefits and learning and development opportunities. Our broad and competitive mix of benefits options is designed to support and protect employees and their families. At CACI, you will receive comprehensive benefits such as; healthcare, wellness, financial, retirement, family support, continuing education, and time off benefits.
The proposed salary range for this position is:
$108,400 - 227,500 USD
CACI is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, pregnancy, sexual orientation, age, national origin, disability, status as a protected veteran, or any other protected characteristic.