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.

This is a 6-month (July 6th - December 18th, 2026) paid co-op experience out of our Boston, MA headquarters.

Our Security Engineering team is looking for a student to join as a Security Engineering Co-op. The co-op program at Klaviyo is designed to provide each student with a meaningful and robust experience that impacts our fellow Klaviyos' experience.

Security Engineering Co-ops dive into substantial projects with concrete goals and objectives that allow plenty of room for exploration and problem solving. You will get exposure to a wide range of tasks involving Front End and Back End engineering. We offer a supportive environment where students can test, fail, iterate and launch while building a solid career foundation, awesome connections across Klaviyo, and have fun.

• Develop internal security tooling in support of Security Operations mission
• Experiment with and incorporate AI technologies into development practices
• Build integrations and automate Security Operations workflows
• Contribute to establishing telemetry data across Klaviyo cloud environments, platforms, and technologies
• Work on big data problems to help identify cyber threats
• Create heuristics and statistical models to find security anomalies
• Ship code in an agile fashion, pairing with various Security Operations or Engineering Teams to craft better software by soliciting feedback
• Work on a cloud first product, learning about scalable platforms and applying those skills in our production security environment
• Help the entire company understand security best practices

• Undergraduate with a target graduation date between December 2026 - May 2028 with a BA/BS in Computer Science, Engineering or similar field
• Have at least one previous internship or co-op experience in Information Security or Security Engineering
• A passion for building security tools and products that matter
• Enjoy working with new technologies ranging from the Front End to backend, and are particularly passionate in multiple stack areas. You show this by having exposure to various technologies and have good instincts to pick the right tool for any job
• Love digging