Senior Security Engineer (Detection & Response)

Who We Are At Justworks, you’ll enjoy a welcoming and casual environment, great benefits, wellness program offerings, company retreats, and the ability to interact with and learn from leaders in the startup community. We work hard and care about our most prized asset - our people. We’re helping businesses get off the ground by enabling them to focus on running their business. We solve HR issues. We’re data-driven and never stop iterating. If you’d like to work in a supportive, entrepreneurial environment, are interested in building something meaningful and having fun while doing it, we’d love to hear from you. We're united by shared goals and shared motivations at Justworks. These are best summed up in our company values, which are reflected in our product and in our team. Our Values If this sounds like you, you’ll fit right in. Who You Are Justworks is looking for an experienced security engineer skilled in detection and response, who can help enhance and mature Justworks’ Security. As a Senior Detection Engineer, you’ll design, build, and maintain the detection logic that powers our platform, conduct proactive threat hunting, and drive continuous improvements across our detection and incident handling workflows. You’ll collaborate closely with IT, Engineering, Platform, and other members of the Security team to identify attacker behaviors, build high‑fidelity detections, and strengthen our defenses. You’ll also play a key role in designing and conducting table‑top exercises, improving processes, and building automation that reduces friction and accelerates response. You’ll help explore how AI can enhance detection, hunting, and operational efficiency. Your Success Profile What You Will Work On Build, tune, and deploy high‑quality detections across our platform Develop and refine detections using telemetry from EDR, threat intel, endpoint & cloud posture platforms and native AWS cloud services Conduct proactive threat hunting to uncover threat actor behaviors and detection gaps Lead security event & incident handling, including triage, investigation, containment guidance, and post‑incident improvements Build automation and tooling to reduce manual effort and improve detection accuracy Drive process improvements across detection engineering, incident response, and telemetry workflows Collaborate with Engineering to ensure high‑quality logging and visibility across AWS environments Explore and prototype AI‑assisted detection and response capabilities Contribute to internal playbooks, documentation, and detection engineering best practices Design and conduct table‑top exercises to validate readiness and strengthen response processes Note: This position will require participation in an on-call rotation. How You Will Do Your Work As a Sr. Detection Engineer, how results are achieved is paramount for your success and ultimately result in our success as an organization. In this role, your foundational knowledge, skills, abilities and personal attributes are anchored in the following: Good judgement - the exercise of critical thinking, analyzing and assessing problems and implications, identifying patterns, making connections of underlying issues, understanding risks and developing mitigation strategies, and taking ownership of the outcome. Resourcefulness - taking a can-do approach, even in the face of obstacles and constraints by assessing what’s in front of you and effectively and efficiently optimizing what you have, whether it's working on something new or thinking about how to do something better. Teamwork and communication - putting our collective best together through documentation, collaboration, relationship-building, listening, empathy, recruiting, and evangelism. Influence and leadership - fostering a community of knowledge-sharing, collaboration, mentorship, and forward-thinking. Skills and knowledge - the capacity to actively learn and apply specific domain knowledge, know-how, and best practices to continually enhance…