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.

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Senior Security Engineer – we are looking for a hands‑on technical expert to join our growing Detection and Response (D&R) Team. This role involves building and maintaining secure, reliable, and scalable detection and response systems, supporting full end‑to‑end detection development, response lifecycle, and threat response operations. You will provide thought leadership, solve complex security challenges, and improve Klaviyo’s overall security posture.

• 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

• 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/Git Hub 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

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.

$141,600 — $212,400 USD

Our salary range reflects the cost of labor across various U.S. geographic markets. 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 addition to base salary, our total compensation package may include participation in the company’s annual cash bonus plan, variable compensation (OTE) for sales and customer success roles, equity, sign‑on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility.

Your recruiter can provide more details about the specific salary/OTE range for your preferred location during the hiring process.

We’re Klaviyo (pronounced clay‑vee‑oh). We empower creators to own their destiny by making first‑party data accessible and actionable like never before. We see limitless potential for the technology we’re developing to nurture personalized experiences in ecommerce and beyond. To reach our goals, we need our own crew of remarkable creators—ambitious and collaborative teammates who stay focused on our north star: delighting our customers.

If you’re ready to do the best work of your career, where you’ll be welcomed as your whole self from day one and supported with generous benefits, we hope you’ll join us.

AI fluency at Klaviyo includes…