Principal Software Engineer

The posting, as Klaviyo wrote it

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.

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Own the technical direction and delivery for Klaviyo's data platform - streaming, batch compute, storage/lakehouse, and governance - now the foundation for autonomous, agent-driven experiences. Klaviyo's data platform processes billions of events daily across billions of consumer profiles for hundreds of thousands of brands, and increasingly that data is consumed not just by people but by a growing number of AI agents acting on customers' behalf. The footprint grows on two axes at once, ever‑larger data volumes and a steady stream of new data scenarios (new sources, domains, and consumption patterns) and your systems have to scale on both.
You'll design and ship systems that are fast, reliable, cost‑efficient, and safe for autonomous access, creating paved roads for data producers and consumers, human and agent alike. This is an individual‑contributor role (no direct reports); you lead through architecture, code, and influence. Expectations align to Lead/Principal IC behaviors: establishing SLOs, driving technical evolution, and acting as the interface across teams.
What You'll Do

• Design and implement core data platform capabilities (e.g., event ingestion/CDC, stream processing, batch orchestration, data lake/warehouse patterns, catalog/lineage, governance, access, and compliance).
• Define and uphold SLOs for data freshness, availability, and correctness; author/run readiness reviews, incident response, and post‑incident learning for your domain.
• Author ADRs/RFCs, land data contracts and schema governance, and standardize connectors and templates that accelerate developer velocity.
• Profile, tune, and right‑size systems for performance and cost; partner with FinOps on unit‑economics guardrails.
• Pair with product teams and analytics/ML to expose the right abstractions and unblock customer value quickly.
• Contribute high‑quality code and reviews; mentor Staff/ Sr. engineers across pillars through example and enablement (not line management).
• Use AI to streamline data workflows, from authoring and test

[…]
n 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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