Director, Application Engineering

Summary

As the Director of Application Engineering, you are the chief architect of Klaviyo's internal technology nervous system. This is a critical, hands-on leadership role focused on evolving our application ecosystem from point-to-point connections to a robust, event-driven integration fabric. Reporting to the CIO, you will lead a world-class team of engineers to deliver sophisticated integrations and build powerful custom tools that drive enterprise-wide automation and efficiency. Your mission is to create a secure, observable, and highly scalable technical foundation that empowers every team at Klaviyo to operate with speed and precision.

What You'll Do

• Lead an Elite Engineering Team: Recruit, mentor, and lead a team of full-stack, application and integration engineers. Foster a culture of engineering excellence, innovation, and full ownership of outcomes.
• Architect the Enterprise Integration Fabric: Design and own the enterprise integration strategy, moving towards an API-first, event-driven architecture. Own the enterprise iPaaS (Integration Platform as a Service) and ensure its reliability and scale.
• Deliver Mission-Critical Integrations: Oversee the full development lifecycle for all integrations touching our core SaaS platforms (Workday, Salesforce, etc.), ensuring they are performant, resilient, and maintainable.
• Drive Custom Solution Development: Spearhead the engineering of bespoke internal applications that solve complex business problems where off-the-shelf software falls short, creating unique operational advantages for Klaviyo.
• Champion Modern Engineering Practices: Establish and enforce rigorous software engineering standards, including modern CI/CD, comprehensive automated testing, proactive security scanning (SAST/DAST), and SLO/SLA-based monitoring.
• Own the Technical Health of the Ecosystem: Assume ultimate ownership for the performance, security, and cost-effectiveness of our integration platforms, custom applications, and API management layer.
• Transform workflows by putting AI at the center, building smarter systems and ways of working from the ground up.

Who You Are

Required Qualifications:

• 10+ years of experience in software engineering, with a deep understanding of distributed systems, cloud architecture, and API design.
• 4+ years of direct people management experience, with a track record of leading and scaling teams of senior engineers.
• Expert-level experience designing and building complex, high-volume integrations and owning an enterprise-grade iPaaS platform (e.g., MuleSoft, Workato, Zapier etc).
• Strong proficiency with both SaaS integration patterns and custom microservice development in a major programming language (e.g., Python, Java, Go).
• Experience building and managing systems within a regulated environment that requires strong security and compliance controls (e.g., SOX, GDPR).
• You've already experimented with AI in work or personal projects, and you're excited to dive in and learn fast. You're hungry to responsibly explore new AI tools and workflows, finding ways to make your work smarter and more efficient.

Preferred Qualifications:

• Hands-on experience with event-driven architectures (e.g., Kafka, Kinesis, Google Pub/Sub) and data primitives architecture.
• Experience with API gateway management (e.g., Kong, Apigee) and establishing an API-first culture.
• Extensive experience developing and deploying applications on public cloud platforms (AWS, GCP), leveraging serverless and containerized architectures.

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