Security Engineer

Join us in bringing joy to customer experience. Five9 is a leading provider of cloud contact center software, bringing the power of cloud innovation to customers worldwide. Living our values everyday results in our team-first culture and enables us to innovate, grow, and thrive while enjoying the journey together. We celebrate diversity and foster an inclusive environment, empowering our employees to be their authentic selves. Our triage pipeline is heavily AI-enriched, so analysts spend little of their day working alerts directly. The role is the work around triage: incident response, detection engineering, response automation, threat intelligence, and building the AI tooling the pipeline runs on. It is closer to a security engineering role than to a conventional SOC analyst role, and we expect you to write code. This position requires the person to work Pacific Time hours (9:00AM - 5:00PM). Responsibilities Incident response. Own incidents end to end: scoping, containment, forensics, write-up, and remediation follow-through. Detection engineering. Write, tune, test, and retire detections. Detection content is version controlled, reviewed, and measured on outcomes rather than alert volume. IR automation. Build playbooks, integrations, and workflows that remove repeated manual steps from the response process. This is a large part of the role. Threat intelligence. Track activity relevant to our environment and convert it into detections, hunts, and hardening work. Threat hunting. Be a contributor to our hypothesis-led threat hunting initiatives. AI-assisted development. Build and improve the agents, prompts, and enrichment logic behind the triage pipeline. Alert triage. A limited amount: escalations the pipeline surfaces, plus the feedback that improves it. Requirements Hands-on security operations experience, including incidents you can walk through in detail. Proficiency in at least one scripting language (Python or equivalent) and a preference for solving recurrin