Senior GTM Partner Systems Engineer

Klaviyo•Boston, MA

3d•$116,000 - $174,000

About The Position

Klaviyo's operational infrastructure, built and managed by our GTM Systems team, powers our GTM engine. We're looking for a Senior Systems Engineer to keep those systems reliable, extensible, and ahead of the business so the teams that depend on them can focus on what they do best. Our GTM Systems team sits at the center of Klaviyo's go-to-market engine, powering the operational infrastructure that connects marketing, sales, partnerships, and customer success. We build and own the systems that enable our teams to move quickly, trust their data, and focus on what matters most: helping our customers grow. Our GTM Systems Partner team is a small group of technical builders owning the Salesforce platform and its integrations across our full GTM stack — from lead routing and lifecycle management to the external-facing partner portal and its integrations with partner management and payment systems data. As a Senior Systems Engineer on the GTM Systems Partner team, you will own the enterprise systems end-to-end — from understanding the business process, to engineering the right solution, to measuring whether it moved the needle. You will own delivery, platform health, and code quality across a GTM stack — including the external-facing partner portal by sizing and building features, maintaining platform health, and shipping reliable integrations across our GTM stack. This is a high-craft, high-ownership role for someone who wants to write great code, drive quality standards, and see their work translate directly to Klaviyo’s goals.

Requirements

Understanding of the business process
Engineering the right solution
Measuring whether it moved the needle
Delivery, platform health, and code quality across a GTM stack
Sizing and building features for the external-facing partner portal
Maintaining platform health
Shipping reliable integrations across our GTM stack
Writing great code
Driving quality standards
Apex
Lightning Web Components
Flow
Integrations
Engineering best practices (DRY, SOLID, KISS)
GitHub-based pull request reviews
Reliable, secure data flows across partner management and payments
Strict access and permission governance
Triage and resolve high-impact platform and data issues
AI tools as part of your daily engineering workflow
Partnering with Product Owner and Architect during story refinement
Mentoring junior developers through code reviews, engineering standards, and pairing

Responsibilities

Own delivery of Salesforce solutions — Apex, Lightning Web Components, Flow, and integrations — from sprint planning through deployment, applying engineering best practices (DRY, SOLID, KISS) and holding a high bar for code quality through GitHub-based pull request reviews.
Develop and maintain integrations between Salesforce and the broader GTM stack, including the external-facing partner portal; ensure reliable, secure data flows across partner management and payments while prioritizing strict access and permission governance.
Triage and resolve high-impact platform and data issues quickly, owning the technical fix and communicating status clearly to the Product Owner and business partners.
Use AI tools as part of your daily engineering workflow to ship faster, explore unfamiliar systems, and automate repetitive work — and help teammates build the same habits.
Partner with the Product Owner and Architect during story refinement to size work accurately, surface technical constraints early, and ensure stories are fully ready before sprint planning.
Mentor junior developers through code reviews, engineering standards, and pairing — accelerating the team's shift to professional-grade, git-based development practices.