Freelance Offensive Security Engineer Jobs in Reston, VA

A World-Changing Company

Palantir builds the world's leading software for data-driven decisions and operations. By bringing the right data to the people who need it, our platforms empower our partners to develop lifesaving drugs, forecast supply chain disruptions, locate missing children, and more.

The Role

Palantir's Offensive Security team probes our own products, infrastructure, and cloud environment the way a real attacker would. As an Offensive Security Engineer, you will test internal applications and infrastructure, chain findings into realistic attack paths, and work directly with the engineers responsible for the affected systems to get issues closed.

A growing part of the team's work is also developing agentic offensive security tooling: LLM-driven systems that encode operator tradecraft and apply it continuously. You will help in the design of that tooling and prove it out on live assessments.

You will also help to coordinate third-party penetration testing engagements, scoping the work with specialized external firms, keeping assessments focused on the risks that matter, and turning their results into concrete remediation.

• Conduct hybrid web application penetration tests that combine source code review with runtime exploitation across our products and internal tooling.
• Perform external network penetration tests against internet-facing infrastructure, identifying exposed services, misconfigurations, and paths to obtain an initial foothold.
• Perform internal network and Active Directory security assessments, identifying privilege escalation paths, lateral movement opportunities, and misconfigurations.
• Assess the security of cloud and containerized infrastructure, including identity, network, and workload configurations.
• Collaborate with detection engineering to validate telemetry and detection coverage against real-world attack techniques uncovered during engagements.
• Scope and manage third-party pentest engagements end-to-end, critically review results, and work cross-functionally to convert findings into prioritized, actionable remediation.
• Partner with engineering to reproduce, prioritize, and verify fixes for the issues that are surfaced.
• Design and build offensive security tooling and automation tailored to Palantir's stack.
• Author clear, actionable write-ups and readouts for technical and non-technical stakeholders, translating findings into business risk and prioritized action.

• Demonstrated strength in web application penetration testing, with the ability to move fluidly between source code review and runtime testing.
• Demonstrated strength in external and internal network penetration testing, from enumerating and exploiting internet-facing attack surface to establishing a foothold and expanding access once inside.
• Hands-on experience with standard offensive security tooling, including Burp Suite, BloodHound/SharpHound, Certipy, Impacket, Responder, Pacu/ScoutSuite, Nuclei, etc.
• A builder's instinct: comfortable writing code to automate testing, develop proof-of-concept exploits, or to fill gaps in existing tooling.
• Working knowledge of how modern software is built and shipped, including CI/CD pipelines and infrastructure-as-code, and an eye for how those systems become attack paths of their own.
• Working knowledge of cloud, container, and orchestration security principles, and an understanding of how common misconfigurations turn into real attack paths.
• Working knowledge of chaining identity and cloud attack paths end to end, from Kerberos abuse, delegation misconfigurations, and ADCS/SCCM exploitation in large multi-domain Active Directory forests through to IMDS abuse, IAM privilege escalation, and SSRF-driven pivots into cloud control planes.
• Offensive security certifications (e.g. OSCP, OSWE), or a track record in CTF competitions or bug bounty programs, are a plus but not required.

• 4+ years of professional experience in offensive security, penetration testing, red teaming, or a closely related field.
• Willingness and eligibility to obtain a U.S. security clearance preferred.
• Proficiency in at least one scripting or programming language (e.g. Python, Go) sufficient to build and adapt your own testing tooling.
• Demonstrated experience assessing the security of cloud (AWS, Azure, or GCP) and containerized (Docker, Kubernetes) environments.
• Excellent organizational instincts, with the ability to keep multiple streams of work moving in parallel and to track each through to verified completion.
• Clear written and verbal communication, including the ability to explain a vulnerability, its impact, and its fix to the engineers who need to act on it.