Sr. Full Stack Engineer (Top Secret Clearance Required)

i3; Huntsville (AL); On-site; USD 120,000 - 180,000; Full time

Job summary

i3 seeks a Senior Full Stack Engineer to design, build, and modernize enterprise applications for a major federal transformation program. You will work across front-end, back-end, APIs, and cloud environments to deliver secure, scalable solutions that meet strict government standards.

You will collaborate with Product, DevSecOps, Cloud, Data, QA, and Migration teams, mentor junior engineers, participate in design reviews and demos, and help implement secure coding, testing, and performance

Qualifications

• Active Top Secret Security Clearance required.
• U.S. Citizenship required.
• Bachelor’s degree and 8+ years of software engineering or full-stack development experience.
• Experience with front-end and back-end solutions using modern frameworks.
• Hands-on experience with APIs, microservices, relational and NoSQL databases.
• Experience with CI/CD pipelines, Git, DevSecOps environments, and automated testing.
• Strong ability to troubleshoot issues across the entire stack.
• Excellent communication and documentation skills.

Responsibilities

• Design, develop, and maintain front-end and back-end components for enterprise applications.
• Build and optimize REST APIs, microservices, and system-to-system integrations.
• Ensure code quality, performance, and maintainability across the full stack.
• Develop cloud-compatible services and applications (AWS preferred).
• Support deployment of pipelines, infrastructure integration, and CI/CD workflows.
• Align application architecture with modernization and cloud migration requirements.
• Collaborate with Scrum Masters, Product Leads, QA Automation Engineers, Cloud Engineers, and Data Engineers.
• Participate in sprint planning, backlog refinement, technical design reviews, and demos.
• Mentor mid-level engineers and support knowledge-sharing across teams.
• Implement secure coding practices, logging, auditing, and data-handling requirements.
• Conduct performance tuning, optimization, and reliability improvements.
• Ensure delivery aligns with federal security standards and program governance.
• Support automated testing and validation of application functionality and integrations.
• Troubleshoot defects across the stack and coordinate with QA to resolve issues.
• Validate readiness for release and major deployment events.
• Develop technical design documents, API specifications, data flow diagrams, and code documentation.
• Maintain full-stack engineering artifacts required for release, sustainment, and audits.
• Provide status updates and technical insights to leadership and cross-functional teams.

Skills

Top Secret Clearance

U.S. Citizenship

Full-stack development

APIs & Microservices

CI/CD

Education

Bachelor’s degree

Tools

Git

AWS

Docker

Kubernetes

DevSecOps

Job description

Senior Full Stack Engineer

Position Description:

i3 is seeking a Full Stack Engineer – Senior to support application design, development, integration, and modernization for a major federal transformation program. This senior role develops secure, scalable, cloud-ready solutions and works across the entire stack—front-end, back-end, APIs, databases, and cloud environments. The Full Stack Engineer collaborates with Product, DevSecOps, Cloud, Data, QA, and Migration teams to deliver mission-critical capabilities that meet federal performance, security, and compliance standards.

Your future duties and responsibilities:

Application & API Development

• Design, develop, and maintain front-end and back-end components for enterprise applications
• Build and optimize REST APIs, microservices, and system-to-system integrations
• Ensure code quality, performance, and maintainability across the full stack

Cloud-Ready Engineering

• Develop cloud-compatible services and applications (AWS preferred)
• Support deployment of pipelines, infrastructure integration, and CI/CD workflows
• Align application architecture with modernization and cloud migration requirements

Technical Leadership & Collaboration

• Collaborate with Scrum Masters, Product Leads, QA Automation Engineers, Cloud Engineers, and Data Engineers
• Participate in sprint planning, backlog refinement, technical design reviews, and demos
• Mentor mid-level engineers and support knowledge-sharing across teams

Security, Performance & Compliance

• Implement secure coding practices, logging, auditing, and data-handling requirements
• Conduct performance tuning, optimization, and reliability improvements
• Ensure delivery aligns with federal security standards and program governance

Testing & Quality Support

• Support automated testing and validation of application functionality and integrations
• Troubleshoot defects across the stack and coordinate with QA to resolve issues
• Validate readiness for release and major deployment events

Documentation & Reporting

• Develop technical design documents, API specifications, data flow diagrams, and code documentation
• Maintain full-stack engineering artifacts required for release, sustainment, and audits
• Provide status updates and technical insights to leadership and cross-functional teams

Required qualifications to be successful in this role:

• Must have an Active Top Secret Security Clearance
• U.S. Citizenship
• Bachelor’s degree and 8+ years of experience in software engineering or full-stack development
• Experience developing both front-end and back-end solutions using modern frameworks
• Hands-on experience with APIs, microservices, relational and NoSQL databases
• Experience with CI/CD pipelines, Git, DevSecOps environments, and automated testing
• Strong ability to troubleshoot issues across the entire stack
• Excellent communication and documentation skills

Preferred Qualifications

• Experience supporting DOJ, FBI, Intelligence Community, or other national-security programs
• Experience with cloud-native architectures (AWS strongly preferred)
• Familiarity with containerization (Docker), orchestration (Kubernetes), or serverless frameworks
• Experience with performance engineering, load testing, or automated quality pipelines
• Knowledge of Python, Java, JavaScript/TypeScript, or similar languages used across full-stack systems