Senior Security Engineer - Detection Engineering

About the role

Fastly's Detection Engineering team builds the detections that catch malicious activity across its environment and drives the investigations that follow. As a Senior Security Engineer, you will design and build AI agents and automations to support detection and response, develop advanced detections, perform threat hunts and lead security investigations. The role is open to candidates in New York, San Francisco, Denver or remote within the US, with a preference for hybrid near a local office.

Key responsibilities

• Develop detections and analytics to identify threats across cloud, container, corporate and edge environments.
• Lead security investigations, analysing complex log sources and telemetry to determine root cause.
• Build AI agents and automations that speed up detection development, triage and incident response.
• Research, evaluate, implement and maintain custom and commercial security tools such as EDR, SOAR and SIEM.
• Conduct threat hunts to discover unknown malicious activity.
• Take part in on-call rotations and be available during core business hours.

Required profile

• Direct experience integrating AI tools, LLMs and automated agents into security workflows to accelerate alert triage and incident response.
• Experience developing, testing and tuning detections with a detections-as-code approach, including version control and CI/CD.
• Proven track record of leading complex security incident investigations, with expertise in log analysis, real-time containment and collecting forensic artifacts.
• Solid grasp of attacker tactics and techniques, with threat hunting or threat modelling experience.

Required skills

• Strong coding in Python or another general-purpose language, building automations for detection and response.
• In-depth knowledge of major public cloud platforms (e.g. AWS or GCP) and Linux, including containers such as Kubernetes and their native logging and security tooling.
• Nice to have: familiarity with CDNs, edge cloud platforms or Fastly products; scalable ETL and data pipelines for security telemetry; deploying AI agents in production.

What we offer

• Estimated salary of $181,220 to $217,464, with possible equity and discretionary bonus participation.
• Medical, dental and vision insurance, family planning and mental health support, Employee Assistance Program, life, disability and accident insurance.
• Flexible vacation, up to 18 days of accrued paid sick leave, 12 paid local holidays and 12 paid wellness days.
• 401(k) with company match and an employee stock purchase program.