Senior Integrations Engineer

_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 change.
• Implement event streaming and event-driven architectures using services such as Amazon EventBridge, SQS, SNS, Kinesis, or Kafka to enable near-real-time data flow between systems.
• Own authentication and security for integrations — OAuth 2.0 flows, JWT, SAML, and disciplined management of keys and secrets — and ensure data handling meets Klaviyo’s security, privacy, and audit requirements.
• Instrument integrations for end-to-end error observability: structured logging, monitoring, alerting, dead-letter handling, and reconciliation, so problems surface before stakeholders report them.
• Participate in incident handling for GTS integrations — triage and mitigate, communicate status to affected teams, and run blameless post-incident reviews that convert root causes into permanent fixes.
• Automate manual work out of quote-to-cash, procure-to-pay, hire-to-retire, and support workflows, using Workato where low-code fits and custom code where it does not.
• Establish and champion integration standards, reusable patterns, and clear technical documentation, and mentor engineers and system administrators across GTS in applying them.

Who You Are

• You have 5+ years building and supporting enterprise system integrations, including hands-on ownership of production integrations across SaaS platforms, cloud services, and internal applications.
• You have deep experience with at least one major iPaaS platform — Workato, MuleSoft, Boomi, or Informatica — and move comfortably between low-code automation and writing custom code when the use case demands it.
• You know integration design patterns well and can explain when to choose synchronous versus asynchronous, event-driven versus batch, or point-to-point versus hub-and-spoke, along with what each choice costs.
• You have strong hands-on experience with REST, Bulk, and GraphQL APIs — designing, building, consuming, paginating, and debugging them at volume.
• You have worked with event streaming and asynchronous messaging, and you understand ordering, delivery guarantees, replay, and idempotency in practice rather than in theory.
• You are fluent in OAuth 2.0 and related authentication flows, and you treat security — least privilege, secret management, data classification, encryption in transit and at rest — as part of the design rather than a review step.
• You write production-quality Python and JavaScript, and you are comfortable building on AWS with services such as Lambda, EventBridge, SQS, S3, and Secrets Manager.
• You have hands-on experience with several of our core systems — Salesforce, NetSuite, Zendesk, Gainsight, Snowflake, Workday, Stripe, Coupa, Zip, Greenhouse, Okta, Jira, or Linear — and you get productive on unfamiliar platforms quickly.
• You build for observability and you have handled real incidents: you have been on call, debugged failures under time pressure, communicated clearly while doing it, and followed through on the root cause.
• You translate complex technical tradeoffs into terms non-technical stakeholders can act on, and you bring them to a decision.
• You take ownership end to end — requirements, design, build, testing, deployment, and long-term support — and you raise risks early.

Nice to Haves

• Certifications or deep platform expertise in Workato Developer, Mulesoft Developer.
• Familiarity with quote-to-cash, revenue recognition, or procure-to-pay processes and the financial controls that surround them.
• Working knowledge of data engineering practices such as Snowflake, dbt, change data capture, or ELT tooling for analytics-facing integration work.
• Experience applying infrastructure as code and CI/CD — Terraform, GitHub Actions — to integration deployments.
• Exposure to compliance-relevant environments such as SOX, SOC 2, or GDPR, including audit trails and segregation of duties.
• Experience in a high-growth SaaS environment where systems, processes, and priorities were changing quickly.

Why This Role Matters

The Senior Integrations Engineer role is pivotal to Klaviyo's strategic growth as it addresses the increasing demand for seamless integration of diverse technology platforms. Successfully integrating various SaaS applications and automating key processes will enable Klaviyo to offer unparalleled data-driven insights and efficiencies to our clients, fostering greater customer loyalty and engagement.

By driving innovation in integrations and automation, this role directly impacts our ability to scale and adapt to the fast-evolving market needs. It empowers us to offer robust, agile, and secure solutions that our customers can trust, ultimately contributing to Klaviyo’s reputation as a leader in personalized marketing solutions. The right candidate will have the opportunity to be at the forefront of transformative technology initiatives, shaping the future direction of our platform, and adding significant value to both the company and our clientele.

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.

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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 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.

Base Pay Range For US Locations:

$132,000—$198,000 USD

_This role may require up to 10% travel for purposes such as new hire onboarding, client or partner work if applicable, team meetings, and industry events. Travel is coordinated in advance._

Get to Know Klaviyo

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 responsible use of AI (including privacy, security, bias awareness, and human-in-the-loop). We provide accommodations as needed._

_By participating in Klaviyo’s interview process, you acknowledge that you have read, understood, and will adhere to our Guidelines for using AI in the Klaviyo interview Process. For more information about how we process your personal data, see our Job Applicant Privacy Notice._

_Klaviyo is committed to a policy of equal opportunity and non-discrimination. We do not discriminate on the basis of race, ethnicity, citizenship, national origin, color, religion or religious creed, age, sex (including pregnancy), gender identity, sexual orientation, physical or mental disability, veteran or active military status, marital status, criminal record, genetics, retaliation, sexual harassment or any other characteristic protected by applicable law._

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