Principal Engineer, Enterprise Scalability (Remote - East Coast Only)

At Klaviyo, we help businesses build stronger relationships with their customers. As our customers grow, our platform needs to support greater data volumes, more demanding workloads, and increasingly complex operations—with the performance and reliability they depend on.

Engineering at this scale takes technical depth, sound judgment, and close collaboration. You’ll work across teams to solve challenging problems, turn architectural improvements into production results, and help build a platform ready for our largest customers.

We are seeking a senior technical leader to own Klaviyo’s approach to enterprise scalability, performance, reliability, and multi-region readiness. Reporting to a VP of Engineering, you will be a senior individual contributor with no direct reports. You will lead through technical expertise, hands-on engineering, and influence, partnering across teams to deliver improvements that matter to our customers.

You will identify and remove major bottlenecks, drive platform-wide architectural changes, and establish clear measures of readiness for our largest tenants and most demanding workloads. Your work will span system design, profiling, implementation, and production rollout. You will also help teams adopt practical tools and repeatable patterns that make performance and reliability part of everyday engineering.

This role suits an experienced engineer who can move between deep technical investigation and clear executive communication, make and defend architectural decisions, and build alignment across teams.

Reports to: VP of Engineering Direct reports: None

• Define what scale readiness means. Establish measurable targets for latency, throughput, error rates, and capacity. Build a shared scorecard and align teams on service-level objectives, error budgets, and performance expectations for critical enterprise workloads.

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