Senior Offensive Cybersecurity Engineer

ADP, Inc.; Huntsville (AL); On-site; USD 140,000 - 210,000; Full time

Job summary

Parry Labs is seeking a Senior Offensive Cybersecurity Engineer to lead authorized security assessments of software, networks, and distributed systems. You will identify vulnerabilities, demonstrate impact, and collaborate with engineers to verify fixes.

The start date is November 2026, reporting to a functional engineering manager with direction from the Chief Engineer. Responsibilities include threat modeling, test scope definition, penetration testing, fuzzing, and documenting reproducible

Qualifications

• Bachelor's degree or equivalent experience in cybersecurity, CS, or engineering.
• 7+ years in security engineering with offensive testing or vulnerability research.
• Experience in authorized penetration testing, protocol analysis, fuzzing, and vulnerability assessment.
• Ability to review Rust or C/C++ code and develop security tooling (Python or systems language).
• Experience analyzing Linux and network behavior (TCP/IP, services, access controls).
• Experience presenting reproducible findings and working with engineering teams to remediate.

Responsibilities

• Develop threat models and security test plans based on system requirements and failure modes.
• Define test scope, rules of engagement, and stop conditions with stakeholders.
• Conduct penetration testing, protocol analysis, and vulnerability research in approved environments.
• Build protocol and parser fuzzing tools; add automated security checks.
• Assess Linux services and network interfaces; review Rust/C/C++ code for weaknesses.
• Evaluate authentication, cryptographic components, and key handling with engineers.
• Document findings, remediation priorities, and retest fixes; preserve evidence.
• Support red-team/blue-team exercises with clear signoffs separate from implementation.

Skills

Threat modeling

Penetration testing

Vulnerability research

Rust/C/C++ review

Python scripting

Linux/network analysis

Security test tooling

Education

Bachelor's degree in cybersecurity or related field

Job description

If you are unable to complete this application due to a disability, contact this employer to ask for an accommodation or an alternative application process.

Senior Offensive Cybersecurity Engineer

Full Time Alexandria, VA, Alexandria, VA, US

2 days ago Requisition ID: 1355

Who Are We?

At Parry Labs we believe the modern combat advantage relies on the speed and scale of open systems. We’re redefining the edge of the ever-changing and increasingly ever-changing battlespace by delivering game changing capabilities to our warfighters through digital engineering, software, and hardware solutions that are essential to our core of being a Digital Systems Integrator.

Born digital and agile, Parry Labs is building a winning team to be the premier provider for Next Generation Mission Systems Integration across air, land, sea, space and cyber.

Are you ready to be an instrumental part of experts in the industry? Join us in the innovation of integration at Parry and apply to help develop the technologies of tomorrow while reaching new heights in your career today.

About the Job

You will lead authorized offensive security assessments of software, network interfaces and distributed mission systems. You will identify vulnerabilities, demonstrate their impact and work with engineers to verify fixes. You will report to a functional engineering manager, with technical direction from the Chief Engineer.

The target start is November 2026.

Duties & Responsibilities

• Develop threat models and security test plans linked to system requirements and potential failure modes.
• Define authorized test scope, rules of engagement and stop conditions with program stakeholders.
• Conduct penetration testing, protocol analysis and vulnerability research in approved test environments.
• Build protocol and parser fuzzing tools. Add repeatable security checks to automated test workflows.
• Assess Linux services and network interfaces. Review Rust or C/C++ code for security weaknesses.
• Evaluate authentication, digital signatures, replay protection and key handling with software and cryptographic engineers.
• Document reproducible findings, impact and remediation priorities. Retest fixes and preserve test evidence.
• Support red-team and blue-team exercises. Keep assessment signoff separate from implementation ownership.

Required Qualifications

• Bachelor's degree in cybersecurity, computer science, engineering or a related field, or equivalent relevant experience.
• 7+ years of security engineering experience, including hands‑on offensive testing or vulnerability research.
• Experience with authorized penetration testing, protocol analysis, fuzzing and vulnerability assessment.
• Ability to review Rust or C/C++ and develop security test tooling in Python or a systems language.
• Experience analyzing Linux and network behavior, including TCP/IP, service configuration and access controls.
• Experience producing reproducible findings, explaining security impact and verifying remediation with engineering teams.
• U.S. citizenship and eligibility to obtain and maintain a U.S. government security clearance if required. An active clearance is not required at hire.

Preferred Qualifications

• Experience testing positioning, navigation and timing (PNT), distributed systems or embedded devices.
• Knowledge of applied cryptography, post‑quantum algorithms, hardware security modules or key management.
• Experience with source‑code security reviews, secure implementation practices or side‑channel analysis.
• Experience with DoD security testing, STIG verification or Risk Management Framework assessment evidence.

Why Join Parry Labs?

At Parry Labs, we foster a culture of curiosity and collaboration. Employees are given the autonomy to leverage their skills in creating state‑of‑the‑art tech solutions that aid in the protection of the American Warfighter. We encourage new and bold ideas that push the status quo. It is this entrepreneurial spirit that drives us.

Parry Labs will support you with workplace flexibility, a commitment to the health and well‑being of you and your family and provide opportunities to work with a purpose. We are committed to supporting your success in both your professional and personal lives with benefits such as education assistance and unlimited paid time off, just to name a few.

Accessibility/Accommodation:

If because of a medical condition or disability you need a reasonable accommodation for any part of the employment process, please send an e‑mail to [e-mail] or call (256) 682‑7145 to let us know the nature of your request and contact information.