About this role
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.
About the Role
At Klaviyo, our mission is to help businesses grow by delivering personalized experiences powered by unique data insights. The ARIA team plays a crucial role in facilitating this mission by ensuring seamless integration of various SaaS systems, databases, and cloud infrastructures, enabling our clients to derive actionable insights and drive their business objectives.
The Senior Integrations Engineer will own how those systems talk to each other. Our landscape spans many systems, including Salesforce, NetSuite, Zendesk, Gainsight, Stripe, Workday, Greenhouse, Coupa, Zip, and Okta, unified through Snowflake, Workato, and a growing set of internal Python, JavaScript services running on AWS. You will design and build the integrations that move data across that estate reliably, securely, and at scale.
This is an architecture-minded build role. You will be trusted to choose the right pattern for each use case — synchronous API call, bulk load, event stream, or scheduled batch — and to explain the tradeoffs behind that choice. You will design API-first, contract-first interfaces that survive change, and instrument everything you ship so failures are visible, explainable, and quickly resolved.
You will partner closely with the Sales Systems, Finance Systems, People Systems, and IT teams, as well as with Product Engineering, translating business processes into resilient technical designs. You will work alongside ARIA's Integration Architect to shape those designs and to define the patterns and standards other engineers build on.
How You’ll Make a Difference
• Design and build integrations across Klaviyo’s GTS landscape — Salesforce, NetSuite, Zendesk, Gainsight, Stripe, Workday, Greenhouse, Coupa, Zip, Okta, Jira, Linear, and Snowflake — using Workato alongside custom Python and JavaScript services on AWS.
• Select the right integration pattern for each use case — request-response API, bulk or batch data movement, event-driven streaming, or publish-subscribe — and document the reasoning and tradeoffs so the decision holds up as requirements evolve.
• Architect scalable, fault-tolerant solutions that absorb growth in volume and complexity without a redesign, with idempotency, retries, backpressure, throttling, and rate-limit handling built in from the start.
• Build and consume REST, Bulk, and GraphQL APIs, taking an API-first, contract-first approach so interfaces are versioned, documented, and safe to