Lead Offensive Security Researcher — Secure by Default

Leadout Capital; San Francisco (CA); On-site; USD 150,000 - 210,000; Full time

Job summary

Leadout Capital is seeking a Senior Offensive Security Researcher with an attacker mindset to identify, analyze, and remediate vulnerabilities across our products and platforms. You will influence design decisions, drive secure-by-default initiatives, and advance application security maturity.

You will lead manual testing, architectural analysis, and threat modeling to uncover root causes and systemic issues, partnering with engineers to implement scalable remediations and secure designs.

Qualifications

• 7+ years of experience in Application Security or Offensive Security.
• Experience independently finding and remediating vulnerabilities in complex applications.
• Deep understanding of Web application security (OWASP Top 10 and beyond), authentication/authorization flaws, API security, injection attacks, logic flaws, and access control bypasses.
• Hands-on experience with manual security testing beyond automated tools.
• Ability to translate complex security findings into clear, actionable guidance for engineers and leadership.
• Strong communication and collaboration skills with a track record of influencing engineering teams.

Responsibilities

• Lead offensive security assessments (manual testing, code review, architectural analysis, threat modeling) across application ecosystems.
• Identify critical, high-impact, and systemic vulnerabilities alongside isolated issues.
• Drive security research to identify emerging attack vectors, abuse cases, and bypass techniques relevant to our apps and platforms.
• Partner with software engineers, tech leads, and architects to explain risk, impact, and exploitability; design and implement effective remediations.
• Ensure fixes are scalable, maintainable, and aligned with engineering realities.
• Lead Secure by Default initiatives by applying guardrails, patterns, and baseline controls; remediate insecure defaults and unsafe configurations.
• Influence application and platform designs early to prevent vulnerabilities before release.
• Set and apply security standards, best practices, and architectural guidance during development.
• Mentor engineers by sharing security knowledge and offensive techniques.
• Collaborate with detection, monitoring, and incident response teams to improve visibility into real-world exploitation.

Skills

Offensive security

Application security

Threat modeling

Code review

Mentoring engineers

Communication

Job description

Leadout Capital is seeking a Senior Offensive Security Researcher with an attacker mindset to identify, analyze, and remediate vulnerabilities across our products and platforms. You will influence design decisions, drive secure-by-default initiatives, and advance application security maturity.

You will lead manual testing, architectural analysis, and threat modeling to uncover root causes and systemic issues, partnering with engineers to implement scalable remediations and secure designs.