Senior Software Engineer, AI Composer Platform

Klaviyo; Boston (MA); On-site; USD 148,000 - 222,000; Full time

Job summary

Klaviyo is seeking a Senior Engineer for the Composer team to help build and scale an AI-powered, in-app conversational platform used by 170,000+ brands. You will own end-to-end software solutions, mentor colleagues, and drive architectural decisions that improve reliability and speed.

Ideal candidates bring 7+ years of software experience, strong front-end and back-end skills, and a passion for AI-native product development.

Qualifications

• 7+ years of experience in a software engineering role.
• Proven track record building high-quality products and systems.
• Experience delivering end-to-end software solutions across front-end and back-end.
• Experience mentoring team members and driving initiatives for growth.
• Experience conducting code reviews and maintaining robust testing and deployment cycles.
• Interest in AI-native product development and practical exposure to LLMs or agentic workflows.

Responsibilities

• Build and ship high-quality, scalable software systems for Klaviyo's Autonomous Marketing platform.
• Provide technical leadership and mentoring across projects, driving quality and pragmatism.
• Contribute to architectural decisions and trade-offs to improve engineering velocity and customer impact.

Skills

7+ years experience

End-to-end software

Front-end & back-end

AI-native product development

Technical leadership

Code reviews & testing

Mentoring teammates

Tools

Python

React

AWS

LLM tooling

Job description

Klaviyo is seeking a Senior Engineer for the Composer team to help build and scale an AI-powered, in-app conversational platform used by 170,000+ brands. You will own end-to-end software solutions, mentor colleagues, and drive architectural decisions that improve reliability and speed.

Ideal candidates bring 7+ years of software experience, strong front-end and back-end skills, and a passion for AI-native product development.