Senior Security Engineer - Detection & Response

Klaviyo is seeking a Senior Security Engineer to join the Detection & Response Team. This engineering role spans the full detection and response lifecycle, leveraging software development practices to build detections, triage alerts, lead investigations, respond to incidents, perform threat hunting, and build tooling. The engineer will work on complex large-scale security challenges across enterprise, cloud, and product environments, and will shape an engineering-first D&R function using AI and

5+ years of hands-on security experience in modern cloud environments. Experience in triaging, responding to cyber threats, large-scale log analysis, incident response, digital forensics, centralized security data lakes, SIEM solutions, writing detections-as-code, data querying (SQL, Splunk), programming (Python, Go), git/GitHub, CI/CD, threat actor tactics. Engineering-first and AI-first approach, strong communication skills, team player with self-managing work ethic.