This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Security Engineer, Insider Threat based in United States. This is a high-impact security engineering role within a fast-paced Threat Detection and Response environment. You will help build and mature an insider threat program designed to protect sensitive data, systems, and infrastructure. The role combines detection engineering, threat hunting, incident response, digital forensics, and security analytics. You will develop scalable detection logic, automation, and models to identify anomalous behavior and data exfiltration. You will collaborate closely with engineering, HR, Legal, and other business teams during complex investigations. The position offers the opportunity to shape security capabilities across a large and technically sophisticated environment. A strong balance of technical depth, investigative judgment, and calm decision-making is essential for success.