Security Engineer

Mosaic.tech; Boston (MA); On-site; USD 120,000 - 180,000; Full time

Job summary

Air Space Intelligence seeks a Security Engineer to harden and maintain cloud and software environments, ensuring compliance with U.S. government security standards.

You will work on AWS GovCloud and GCC High, supporting NIST 800-171/CMMC and 800-53, and collaborate with product, platform, and compliance teams in a Boston-based office. Ideal candidates have strong Python or Rust skills, container security experience, and familiarity with SBOM, threat modeling, and IaC tools like Terraform.

Qualifications

• Candidates experienced with modern cloud security and government-facing environments.
• Proven ability to harden cloud and software stacks to meet government standards (NIST 800-171/CMMC, NIST 800-53).
• US citizenship and eligibility for DoD clearance are required.

Responsibilities

• Harden and maintain cloud and endpoint environments (AWS GovCloud, Microsoft GCC High).
• Support compliance with U.S. government security standards (NIST, CMMC, FedRAMP).
• Lead threat modeling sessions and security reviews throughout the SDLC.

Skills

Python

Rust

Kubernetes

CI/CD security

Vulnerability scanning

SBOM

Threat modeling

Terraform

FedRAMP/NIST

AWS GovCloud

Incident response

SIEM

Tools

AWS GuardDuty

Splunk

Microsoft Sentinel

Terraform

Job description

About Air Space Intelligence

ASI's mission-critical technology powers decision-making across aviation, defense, energy, and other critical infrastructure domains. Backed by top-tier investors including Andreessen Horowitz, Spark Capital, and Renegade Partners, ASI delivers operational decision superiority—compressing days of analysis into seconds of action. ASI is leading the way and pushing the boundaries of what’s possible.

What You Will Do

Air Space Intelligence is building mission-critical, secure infrastructure for defense and intelligence applications. We are seeking a Security Engineer to harden and maintain cloud and software environments, ensuring compliance with U.S. government security standards. As a Security Engineer, you will help harden and maintain ASI’s cloud and endpoint environment (AWS GovCloud and Microsoft GCC High) while supporting compliance with U.S. government security standards (e.g., NIST 800-171/CMMC and NIST 800-53).

What We Value

• Demonstrated coding skills in Python/Rust

• Knowledge of container and CI/CD security (Kubernetes, image hardening, vulnerability scanning)

• Investigate & remediate vulnerabilities, escalating complex issues when needed

• Supply chain security experience (SBOM, artifact generation, dependency management)

• Lead threat modeling sessions using established industry methodologies (e.g., STRIDE, PASTA, etc.)

• Demonstrated skills in Infrastructure as a code (Terragrunt/Terraform).

• Practical exposure to federal security frameworks (CMMC, NIST 800-53, FedRAMP).

• Experience securing government cloud environments (AWS GovCloud), ensuring compliance with federal security requirements.

• Hands-on experience with cloud-native incident alerting services (e.g., AWS GuardDuty/Security Hub, Azure Defender, etc.)

• Automate configuration management, patching, and policy enforcement for networks, servers, and endpoints

• Monitor security events using SIEM tools (Microsoft Sentinel, Splunk)

• Collaborate with product, Platform, and compliance teams to embed security in the SDLC

• Support incident response and post-incident review, growing toward leading these efforts over time

How we hire:

We view the interview process not as a screening or test, but rather as an opportunity to simulate what it would be like working together. We build the interview process around you.

ADDITIONAL REQUIREMENTS

• Security Clearance: Must be eligible to obtain DoD clearance.

• Citizenship: U.S. citizenship is required for this position.

• On-Site Presence: Ability to work in our Boston (BOS) office at least three days per week