Senior Software Engineer

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 role involves owning the design, implementation, and continuous evolution of Klaviyo's AI-native Customer Agent platform. You will architect and deliver systems that enable autonomous service, AI-driven support, and agentic commerce experiences across millions of customer touchpoints. This position requires driving technical strategy for complex workflows, multi-channel conversational experiences, and integrations with retrieval and observability systems. You will evaluate architectural trade-offs, prototype multiple solution paths, and ensure that deployed solutions meet high standards for scalability and reliability. Additionally, you will act as a technical leader and mentor, influencing engineering quality and decision-making across cross-functional teams. Success in this role is defined by your ability to ship high-quality systems quickly while shaping how AI-powered customer engagement evolves at scale.

Key facts

What you'll do

Design and build core platform capabilities for Klaviyo's Customer Agent, including conversational experiences, intelligent workflows, and tools integrations.

Architect and scale retrieval systems, onboarding flows, and multi-channel customer engagement features that support brand-specific agent configurations.

Develop and maintain observable, reliable systems for AI-driven support that balance performance, scalability, and customer impact.

Lead technical decision-making for complex product challenges while evaluating business requirements and engineering constraints.

Mentor engineers, drive code quality through reviews, and promote a robust testing and deployment cycle across the team.

Collaborate closely with product, design, data science, and go-to-market teams to solve ambiguous problems with urgency and pragmatism.

Implement solutions that enable brands to launch, customize, and continuously improve their own highly-configurable AI agents across chat, email, SMS, and other channels.

Continuously explore AI-native development practices, including experimentation with LLMs, agentic workflows, and tooling to improve engineering velocity.

Champion a product-first mindset that aligns technical outcomes with customer needs and long-term platform extensibility.

Drive ownership of end-to-end delivery, from initial concept through deployment and iteration, in a fast-moving, startup-like environment.

Maintain a bias toward execution by shipping incremental value while iterating on feedback and evolving system designs.

Contribute to the strategic direction of one of Klaviyo's most ambitious product areas by defining standards for AI-powered customer engagement.

Ensure solutions are reliable, scalable, and maintainable by investing in observability, testing, and thoughtful architectural choices.

Act as a technical leader who inspires cross-functional collaboration and helps the team move faster through clarity and ownership.

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 have 7+ years of experience in a software engineering role spanning both front-end and back-end responsibilities or deep full-stack expertise.

You must demonstrate experience developing end-to-end software solutions that are scalable and customer-facing in fast-paced product environments.

You must have experience operating like a startup inside a larger organization, embracing rapid iteration cycles and high ownership.

You must show a history of leading projects and being accountable for technical and business outcomes through delivery and iteration.

You must have experience mentoring team members or driving initiatives that help the group grow, learn new skills, and improve engineering practices.

You must have hands-on experience conducting code reviews and maintaining a robust testing and deployment lifecycle.

You must exhibit 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 while maintaining a strong product mindset.

Nice to have

Skills with Python and related technologies.

Skills with React and related technologies.

Experience with AI tooling, agentic systems, and prompt engineering in professional settings.

Experience building extensible platform products and developer-facing APIs.

Experience contributing to open source or publishing technical work in the AI or full-stack space.

Familiarity with data pipelines, observability tools, and deployment workflows for machine learning-enabled systems.

Practical notes

The role operates in a full-time capacity from Klaviyo's Boston, MA office.

Travel requirements, visa sponsorship details, and application deadlines were not specified in the available source material.