Sr. Technical Investigator, Trust Investigations Account Security

Sr. Technical Investigator, Trust Investigations Account Security

At Linked In, our approach to flexible work is centered on trust and optimized for culture, connection, clarity, and the evolving needs of our business. The work location of this role is hybrid, meaning it will be performed both from home and from a Linked In office on select days, as determined by the business needs of the team. This role will be based in Mountain View, CA.

Trust Investigations is seeking a Senior Technical Investigator to support our work protecting member accounts. In this role, you'll develop and apply approaches to detect, understand and mitigate coordinated, persistent, and high-harm attacks against account access and authentication, helping ensure a safe and trustworthy experience for Linked In members.

Our teams work closely with product, engineering, and data science partners dedicated to advancing our visibility, controls and measurement across login, authentication, and account recovery. In this role you will run investigations and contribute to building our technology as we operate an AI-first trust environment: you'll lead complex investigations and incidents, using case insights to develop and maintain our detection rules, pipelines, and runbooks that help Linked In stop account takeover (ATO) and account rental activity at scale.

Our investigations drive product vulnerability assessments and risk recommendations, so you'll work with our intelligence teams, engineers focused on challenges and controls, and product-risk teams to ensure findings inform how the company builds and protects its login, MFA, and account recovery experiences going forward.

Key Responsibilities

• Lead root-cause investigations into complex, coordinated, or high-impact account security campaigns, including account rental/seat-sharing networks, from initial leads through resolution.
• Serve as incident commander for major account-compromise incidents, coordinating response and ensuring timely, accurate resolution and member remediation.
• Generate proactive investigative leads and track emerging coordinated threat activity relevant to account authenticity, security and trust.

Detection Engineering & Technical Tradecraft

• Author detection rules and data pipelines tuned specifically to ATO patterns and typologies like session hijacking, MFA bypass, and device/network fingerprint anomalies.
• Innovate on investigative tradecraft, staying current on tools, techniques, and adversary tactics used across the account takeover and credential-abuse landscape broadly.
• Partner with Engineering and Data Science to build and refine analysis, threat-hunting, and mitigations for account abuse.
• Develop technical playbooks that help the broader team scale its investigative work across account takeover, recovery, and rental abuse.

Cross-Functional Partnership & Vulnerability Reporting

• Partner with internal investigators and product-risk teams to ensure investigative findings and intel inform product planning and risk posture.
• Collaborate with Product, Engineering, Data Science, Legal, and Policy partners to align investigative priorities with the teams' roadmap and the broader trust strategy.
• Represent the technical substance of your team's work in cross-functional forums and externally to peers in the sector.

Quality & Mentorship

• Mentor other investigators on technical, investigative, and tooling capabilities, fostering a culture of rigor and continuous learning.

Basic Qualifications

• Bachelor's Degree in a related technical discipline, or equivalent practical experience.
• 5+ years of experience with scripting or data analysis tools (SQL, Python, or similar), with the ability to synthesize complex data into actionable insights.
• 5+ years of experience in proactive threat investigations of account, content, or behavioral abuse in trust & safety, social media, online platforms, or fintech — including meaningful direct experience with account takeover, credential compromise, or authentication abuse.
• 3+ years of experience with investigation techniques/tools and evidence handling, including working across diverse structured and unstructured data sets.

Preferred Qualifications

• Master's Degree in Cyber Security, Criminal Justice, Computer Science, or a related technical discipline.
• Direct experience building or maintaining detection rules, alerting logic, or data pipelines (not just consuming them).
• Strong technical acumen and the ability to translate data and investigative outcomes into actionable insights for engineering, AI, and senior leadership partners.
• Experience leading proactive threat hunting against large-scale, coordinated account takeover or credential-abuse operations.
• Familiarity with authentication and session security concepts (MFA/2FA, passkeys, device/session fingerprinting, cookie and token security) and how they're exploited or defended.
• Experience with frameworks such as MITRE ATT&CK or the cyber kill chain, and the ability to adapt them to account takeover and…