Senior Security Engineer - Detection and Response

At Klaviyo, we value the unique backgrounds, experiences and perspectives each Klaviyo (we call ourselves Klaviyos) brings to our workplace each and every day. We believe everyone deserves a fair shot at success and appreciate the experiences each person brings beyond the traditional job requirements. If you’re a close but not exact match with the description, we hope you’ll still consider applying. Want to learn more about life at Klaviyo? Visit klaviyo.com/careers to see how we empower creators to own their own destiny. Klaviyo is looking for a Senior Security Engineer to add to our growing Detection and Response (D&R) Team. This is a hands-on technical role that involves building and maintaining secure, reliable, and scalable detection and response systems to enhance our security observability capabilities. This role will also be responsible for participating in full end-to-end detection development and response lifecycle and support with threat response operations. As a Senior Security Engineer, you will have the opportunity to leverage your security and engineering skills to provide thought leadership, solve complex security challenges and ultimately improve Klaviyo’s overall security posture. How you will make a difference: • Build systems that facilitate security observability for detection and response • Develop AI-first security systems to automate detection and response operations • Onboard, normalize and optimize security logging data for large-scale data analysis, detection engineering, deployment of ML models, and efficient querying during incidents. • Develop high-fidelity rule-based and/or ML-based detections as code • Respond to security alerts, cyber threats, and security incidents • Drive end-to-end incident response investigations • Automate and codify detection and response workflows and processes • Conduct ad-hoc threat hunts and be an active member of D&R on-call rotations We’d love to hear from you if you have: • 5+ years of experience in software, security, and/or data engineering • Automation-first and AI-first approach for all work performed • Experience with centralized logging, data lakes, and SIEM solutions • Familiarity with large-scale data pipelines and data engineering techniques • Proficient in programming languages to automate / build (e.g., Python, Go or similar) • Proven experience with git/GitHub and CI/CD automations • Familiarity with tactics, techniques, and procedures used by threat actors • Experience being part of detection and response or incident response on-call • Strong passion for continuous learning and staying updated on evolving technology • Strong oral and written communication skills • Team player with a strong, self-managing work ethic We use Covey as part of our hiring and / or promotional process. For jobs or candidates in NYC, certain features may qualify it as an AEDT. As part of the evaluation process we provide Covey with job requirements and candidate submitted applications. We began using Covey Scout for Inbound on April 3, 2025. Please see the independent bias audit report covering our use of Covey here Massachusetts Applicants: It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability. Our salary range reflects the cost of labor across various U.S. geographic markets. The range displayed below reflects the minimum and maximum target salaries for the position across all our US locations. The base salary offered for this position is determined by several factors, including the applicant’s job-related skills, relevant experience, education or training, and work location. In additio