Senior Full-Stack Engineer for AI-Powered Platforms

Klaviyo Inc.; Boston (MA); Hybrid; USD 148,000 - 222,000; Full time

Job summary

Klaviyo is seeking a Senior Full Stack Engineer to help build the future of Customer Agent, Klaviyo’s AI-native conversational platform. In this role, you’ll shape autonomous service and AI-driven support experiences across millions of customer interactions, working across the stack to design scalable systems.

You’ll lead technical initiatives, mentor teammates, and prioritize reliability and performance while shipping high-quality solutions that improve engineering velocity and customer

Qualifications

• 7+ years of experience in a software engineering role.
• Experience leading projects and being accountable for technical and business outcomes.
• Experience building scalable, customer-facing systems in fast-moving product environments.
• Curiosity and enthusiasm for AI-native product development, including practical experience with LLMs or agentic workflows.

Responsibilities

• Design, build, and scale systems powering AI-native agent experiences.
• Collaborate across engineering, product, design, data science and GTM teams.
• Mentor teammates and drive engineering quality, execution, and decision-making.

Skills

Full stack development

Frontend development

Backend development

AI-native systems

Mentoring/leadership

Code reviews & testing

Python

React

LLM tooling

Tools

AWS

LLM tooling

Job description

Klaviyo is seeking a Senior Full Stack Engineer to help build the future of Customer Agent, Klaviyo’s AI-native conversational platform. In this role, you’ll shape autonomous service and AI-driven support experiences across millions of customer interactions, working across the stack to design scalable systems.

You’ll lead technical initiatives, mentor teammates, and prioritize reliability and performance while shipping high-quality solutions that improve engineering velocity and customer