Senior Software Engineer, Customer Agent

About the 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. The team is looking for a Senior Full Stack Engineer to help build the future of Customer Agent, Klaviyo's AI-native conversational platform. In this role, you will play a critical part in shaping how autonomous service, AI-driven support, and agentic commerce experiences evolve at scale across millions of customer interactions. You will work across the stack to design, build, and scale systems that power intelligent workflows, conversational experiences, tools integrations, retrieval systems, onboarding flows, observability, and multi-channel customer engagement. You will help develop both foundational platform capabilities and customer-facing experiences that enable brands to launch, customize, and continuously improve their own highly-configurable AI agents.

Key facts

What you'll do

You will architect and implement core platform components that enable scalable, reliable, and secure customer agent experiences across digital channels. You will translate ambiguous product requirements into robust technical solutions while balancing trade-offs between speed, quality, and long-term maintainability. You will partner closely with product managers, designers, and data scientists to prototype and iterate on AI-driven features that directly impact customer engagement and retention. You will own the full lifecycle of critical services, from initial design and implementation through deployment, monitoring, and continuous optimization in production environments. You will contribute to code reviews, define architectural patterns, and mentor engineers to uphold high standards of quality and reliability across the codebase. You will build and maintain integrations with third-party AI services, CRM systems, and messaging platforms to ensure seamless interoperability and extensibility. You will implement observability, logging, and debugging tooling that empowers product teams to diagnose issues and improve agent behavior in real time. You will collaborate with customer-facing teams to understand emerging use cases and translate them into resilient, configurable workflows that support brand-specific experiences.

Requirements

You must possess a proven track record of building high-quality products and systems, with pride in writing clean, maintainable, high-quality code. You must bring 7+ years of experience in a software engineering role. You must demonstrate strong experience developing end-to-end software solutions or extensive experience across both front-end and back-end technologies. You must have experience building scalable, customer-facing systems in fast-moving product environments, acknowledging that we operate like a startup inside of Klaviyo. You must have experience leading projects and being accountable for technical and business outcomes. You must have experience mentoring team members or driving initiatives that help the team grow and learn new skills. You must have experience conducting code reviews and maintaining a robust testing and deployment cycle. You must show curiosity and enthusiasm for AI-native product development, including practical experience experimenting with LLMs, AI tooling, or agentic workflows in professional or personal projects. You must be excited about leveraging AI to improve engineering velocity, customer experiences, and operational workflows. You must possess a strong product mindset and willingness to collaborate cross-functionally to solve ambiguous problems with urgency and pragmatism.

Nice to have

The role mentions skills with Python and related technologies as well as skills with React and related technologies as preferred but not required qualifications.

Practical notes

The engagement type is listed as See source in the original job posting, and the location is specified as Boston, MA. No information about hours, travel, visa, or deadlines was provided in the source material.