Senior Software Engineer Customer Agent

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 youre a close but not exact match with the description we hope youll still consider applying. Want to learn more about life at Klaviyo Visit see how we empower creators to own their own destiny.

About the Role

Our team is looking for a Senior Full Stack Engineer to help build the future of Customer Agent Klaviyos AI-native conversational this role youll play a critical part in shaping how autonomous service AI-driven support and agentic commerce experiences evolve at scale across millions of customer interactions.

Youll 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. Youll 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.

As a Senior Engineer youll tackle complex technical and product challenges develop multiple solution paths and evaluate business and architectural trade-offs to determine the best approach. Youll also act as a technical leader and mentor driving engineering quality execution and decision-making across projects. Additionally youll be responsible for deploying well-designed thoroughly tested solutions that prioritize reliability scalability and customer impact.

The Customer Agent team is building one of Klaviyos most ambitious and strategic product areas: an extensible AI platform that enables brands to deliver personalized autonomous customer experiences across channels like chat email SMS and beyond. We operate with high ownership rapid iteration cycles and a strong bias toward execution. Every engineer is expected to think holistically about customer outcomes collaborate deeply across engineering product design data science and go-to-market teams and push beyond traditional role boundaries to help the team move faster.

Success in this role means shipping high-quality systems quickly contributing to foundational platform decisions improving the intelligence and reliability of our agent experiences and helping define how AI-powered customer engagement evolves at Klaviyo.

What Were Looking For

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

Nice to Have

• Skills with Python and related technologies.
• Skills with React and related technologies.
• Experience building conversational AI systems workflow engines or agentic platforms.
• Experience with retrieval systems embeddings eval frameworks or LLM orchestration patterns.
• Experience building cloud-native solutions ideally with AWS.
• Experience developing customer support commerce marketing or customer data software solutions.
• Experience with machine learning systems or AI infrastructure.
• Experience building multi-tenant or highly configurable SaaS platforms.
• Familiarity with observability tracing experimentation or AI quality/evaluation tooling.

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