Senior Security Engineer - Cloud & Threat Defense

i3; Chantilly (VA); On-site; USD 150,000 - 230,000; Full time

Job summary

i3 is seeking a Senior Security Engineer to strengthen security across enterprise applications, cloud environments, and critical infrastructure. You will lead proactive monitoring, threat detection, and incident response while guiding security modernization and governance.

Ideal candidates bring TS clearance, 8+ years of hands-on security engineering experience, and strong skills in AWS/Azure/GCP, SIEM, and secure development with modern languages.

Qualifications

• Bachelor's degree in a relevant field required.
• Minimum 8 years of experience securing applications, cloud platforms, networks and enterprise infrastructure.
• US Citizen with a Top Secret Clearance.
• Experience with AWS, Azure, or Google Cloud."
• Proficiency with security monitoring, logging, SIEM and alerting tools.
• Strong understanding of network security, encryption, authentication, and access control.
• Experience with in-house custom-developed applications and advanced AI, GenAI, and multi-model engineering.
• Data architecture expertise including vector, graph, and multi-database orchestration.
• Experience with air-gapped, hybrid, and on-premise environments.
• Application development and integration knowledge using TypeScript, React, Python, FastAPI.

Responsibilities

• Secure applications, cloud platforms, networks, and enterprise infrastructure.
• Lead incident response, cyber resiliency, vulnerability management, and threat detection efforts.
• Design and implement security controls and support cloud-based platforms (AWS, Azure, GCP).
• Utilize security monitoring, logging, SIEM, and alerting tools effectively.
• Develop security policies, procedures, and technical documentation.
• Provide technical mentorship and ensure alignment with defense-in-depth and security policies.
• Engage in multi-model and multi-modality orchestration, including advanced AI implementations.
• Manage enterprise infrastructure and cross-domain solutions, including air-gapped and hybrid environments.
• Develop and integrate applications with modern programming languages and frameworks.

Skills

Top Secret Clearance

Security analysis

Threat detection

Incident response

Data architecture

TypeScript

React

Python

FastAPI

Education

Bachelor's degree

Master's degree

Tools

SIEM

Security monitoring

Cloud platforms

Job description

i3 is seeking a Senior Security Engineer to strengthen security across enterprise applications, cloud environments, and critical infrastructure. You will lead proactive monitoring, threat detection, and incident response while guiding security modernization and governance.

Ideal candidates bring TS clearance, 8+ years of hands-on security engineering experience, and strong skills in AWS/Azure/GCP, SIEM, and secure development with modern languages.