Sr. Full Stack Engineer; Top Secret Clearance Required

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, Dev Sec Ops , Cloud, Data, QA, and Migration teams to deliver mission-critical capabilities that meet federal performance, security, and compliance standards.

• 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

• 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 No
  
  SQL databases
• Experience with CI/CD pipelines, Git, Dev Sec Ops  environments, and automated testing
• Strong ability to troubleshoot issues across the entire stack
• Excellent communication and documentation skills

• 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/Type Script, or similar languages used across full-stack systems