Lead Software Engineer - New Products

Klaviyo • Boston, MA

7d

About The Position

We’re looking for a Lead Software Engineer to set technical direction and drive delivery for some of Klaviyo’s most ambitious new product initiatives. In this role, you’ll operate as a technical owner for major product areas—shaping architecture, guiding execution, and ensuring that teams deliver high-impact, high-quality solutions at speed.
You’ll partner closely with Product, Design, and Engineering leadership to translate bold ideas into scalable systems. As a Lead, you’ll tackle the most complex technical challenges, make high-stakes trade-off decisions, and raise the bar for engineering excellence across the New Products organization. You’ll also be a force multiplier—mentoring senior and mid-level engineers, influencing best practices, and helping the team move faster and smarter.
The New Products team drives Klaviyo’s most ambitious innovations—creating and scaling the company’s boldest new bets. As a nimble group with a flat structure and fast-moving culture, we prioritize simplicity, speed, and impact. Every team member is expected to take radical ownership—rolling up their sleeves, collaborating across disciplines, and pushing beyond traditional role boundaries to make things happen. Success in this role means setting the standard for technical leadership, execution velocity, and product quality while helping shape Klaviyo’s future through experimentation, creativity, and disciplined execution.

Requirements

• A strong track record of building and scaling high-quality products and systems.
• 8+ years of professional software engineering experience.
• Deep experience designing and delivering complex, end-to-end solutions.
• Proven ability to lead large projects or technical domains with accountability for outcomes.
• Experience influencing technical direction beyond your immediate team.
• Strong mentoring and coaching skills, especially for senior engineers.
• Expertise in code reviews, testing strategies, and production readiness.
• Comfort operating in fast-paced, ambiguous environments.
• Hands-on experience experimenting with AI tools and workflows, with a strong interest in building AI-centered systems and processes.

Nice To Haves

• Strong experience with Python and related technologies.
• Strong experience with React and modern frontend frameworks.
• Experience building digital marketing or customer data platforms.
• Experience with machine learning or applied AI systems.
• Experience building cloud-native systems, ideally on AWS.

Responsibilities

• Own technical strategy and architecture for major product initiatives.
• Lead the design and delivery of complex, end-to-end systems across frontend and backend.
• Drive critical technology decisions, balancing long-term vision with near-term execution.
• Mentor senior and mid-level engineers, supporting their growth and raising team-wide standards.
• Partner with Product and Design to shape product direction and technical feasibility.
• Establish and reinforce best practices for code quality, testing, reliability, and performance.
• Champion the use of AI-first workflows and systems, responsibly integrating new tools to improve developer productivity and product capability.

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level
• Education Level: No Education Listed
• Number of Employees: 501-1,000 employees