Lead Software Engineer, Messaging Infrastructure

About Klaviyo

Klaviyo is a forward-thinking marketing automation platform dedicated to empowering creators by providing personalized customer experiences that drive business growth. Our engineering culture prioritizes exceptional developer experiences, encouraging efficient, high-quality software delivery.

Role Overview

Within the Messaging Infrastructure division, you will lead and innovate to scale Klaviyo's messaging systems—including email, SMS, mobile push, WhatsApp, and more—that deliver billions of messages reliably. As Lead Software Engineer, you will provide hands-on technical leadership, guide architectural decisions, and mentor engineers to elevate the messaging platform, ensuring compliance with regulations and seamless provider integrations.

Key Responsibilities

• Own the design and architecture of crucial components in the messaging pipeline, from message ingestion to routing, delivery, and status tracking.
• Lead and scale engineering teams to build highly available and high-throughput services spanning multiple messaging channels.
• Develop scalable backend services primarily in Python and/or Go.
• Manage a campaign pipeline processing hundreds of millions of messages daily, scaling towards billions.
• Disentangle complex technical challenges into clear actionable plans.
• Partner with product, compliance, deliverability, and platform teams to expand messaging capabilities.
• Promote engineering best practices in system design, code quality, and development processes within your team.
• Provide mentorship and foster growth among engineers to maintain high standards across the Messaging Infrastructure organization.
• Integrate artificial intelligence workflows and systems to enhance team efficiency and product quality.

Qualifications

• Minimum eight years of engineering experience, with solid expertise in backend and distributed systems design.
• Proficiency in Python and/or Go programming languages, with the ability to quickly learn the other.
• Extensive experience in architecting large-scale systems, balancing technical trade-offs with business needs.
• Hands-on approach with both architectural leadership and coding contributions.
• Experience scaling infrastructure using AWS services.
• A product-focused mindset, understanding customer impact beyond coding.
• Self-driven and focused on delivering incremental value iteratively.
• Excellent communication skills thriving in autonomous, cross-functional environments.
• Previous experience experimenting with AI technologies and enthusiasm for ongoing AI integration.

Technical Environment

• Programming Languages and Frameworks: Python, Django, React
• Data & Infrastructure Tools: MySQL, Redis, Memcached, Apache Zookeeper, Apache Pulsar
• Cloud & DevOps: Amazon Web Services (EC2, RDS, Aurora), Terraform, Jenkins

Additional Information

This role is located in Dublin, Ireland, and follows a hybrid work model. The company supports work authorization and relocation assistance. The position may require up to 10% travel for activities such as onboarding, client engagements, team meetings, and industry events, with travel arranged in advance.

Klaviyo offers a competitive salary ranging from €112,000 to €168,000 EUR annually, reflecting local labor market conditions and considering skills, experience, education, and location. Compensation may also include bonuses, equity, sign-on payments, and a comprehensive suite of benefits.

Our commitment to diversity ensures equal opportunity and non-discrimination for all applicants regardless of background. We prioritize privacy and security during the application process and caution against fraudulent offers.

Company Culture

At Klaviyo, we promote inclusion, ownership, continuous learning, and teamwork. Candidates with diverse experiences and backgrounds are encouraged to apply and thrive within our fast-growing organization focused on providing meaningful technology solutions.