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Lead Software Engineer - Integrations

  • Boston, MA
  • Engineering

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 you’re a close but not exact match with the description, we hope you’ll still consider applying. Want to learn more about life at Klaviyo? Visit to see how we empower creators to own their own destiny.

Team Overview 

The Integrations team is responsible for building and maintaining Klaviyo’s integrations to a variety of 3rd party vendors. These vendors can be grouped across a number of industries such as ecommerce, point of sale, payment processing, advertising, and fundraising. In order to enable our customers to integrate with these different vendors we provide easy-to-use interfaces that guide our customers through the setup and management of an integration. Behind the scenes, we use a variety of pipelines to process data flowing to and from these vendors at scale. We collaborate closely with internal stakeholders and have substantial exposure to Klaviyo's customers, including businesses, partners, and third-party developers.

How you’ll make an impact

The Integrations team operates at the intersection of distributed systems, software architecture data mapping & pipelining, scalability, and reliability. As a Lead Software Engineer, you will own and drive our technical vision of building thousands of integrations across various verticals in a fast, flexible, efficient, and maintainable way, resulting in world class customer and developer experiences. Critical components of the Integrations space include Klaviyo’s V3 APIs, 3rd party vendor’s APIs, inbound and outbound data pipelines, and data mapping and transformation. You will have an opportunity to learn our existing end-to-end integration workflow and help scale it up to support the next evolution of Klaivyo’s growth into several verticals beyond e-commerce. You’ll work closely with a team of talented software engineers, data scientists, product managers, and UX/UI designers who are eager to make the process of integrating with Klaviyo fast, efficient, and seamless. Your technical leadership, outside-the-box thinking, and execution will help shape Klaviyo’s trajectory for the next decade.

Who you are

  • You are passionate about building software effectively and for the long-term. 
  • You have 10+ years of hands-on software development experience creating and maintaining highly available, full-stack SaaS products at scale.
  • You have 2+ years of experience as a team lead, leading and delivering complex cross-team software projects spanning multiple quarters.
  • You have been a successful interface between the team and the rest of your product area. You have been responsible for the entire lifecycle of projects or features including design, development, and deployment, providing direction for others.
  • You have successfully owned and driven the technical vision for your product area. You are able to wear the architect hat during the design phase but also put on the IC developer hat during the implementation phase. 
  • You are an excellent communicator. Through effective communication, thought leadership, and consensus building, you have successfully been able to align your team behind your vision.
  • You like to question convention, proactively find ways to innovate, and are intrinsically motivated to drive incremental improvements that deliver value to the business.
  • You like working on small, autonomous agile teams. Enjoy shipping code early and often in an agile fashion, pairing with product management, business stakeholders, and other engineers to craft better software.
  • You are a natural leader and mentor to other software engineers on your team. You know when to keep a task for yourself and when to delegate effectively and set others up for success. You continue to push yourself and your team to grow, collaborate, and get better.
  • You have an in-depth understanding of commonly used web architecture design patterns when it comes to highly scalable systems. You have proven expertise in applying those design patterns to implement highly-scalable multi-tenant systems.
  • You like creating, teaching, and improving shared engineering processes. 
  • You are successfully able to estimate and manage project timelines and risks to ensure the team will be in a position to deliver on its commitments.

What You’ll do:

  • Have an opportunity to make a major impact on the direction and priorities of the Integrations team –  wholly owning features that 100,000+ customers rely on daily to reach 4B+ consumers to drive their business forward.
  • Responsible for the technical/architectural ownership and evolution of our product area, anticipating scalability and reliability needs; contributing to the roadmap while collaborating alongside technical product owners and product managers.
  • 70% hands-on code delivery, 20% design/architecture, and 10% cross-team collaboration and mentorship.
  • Responsible for building and managing Klaviyo’s integration settings pages, API services that communicate with 3rd-party vendor APIs, data transformation of data flowing between Klaviyo and the 3rd-party vendors, as well as wiring up the API Services into a number of data pipelines.
  • Contributing to the creation of APIs, Toolkits, and SDKs that will allow the Integrations team to create thousands of integrations across various verticals in a fast, flexible, efficient, and maintainable way.
  • Build prototypes, establishes design patterns, consults with domain experts and otherwise works to ensure a team's successful delivery of technical solutions. 
  • Provide quality PR reviews for our code-owned areas of the application.
  • Represent the Integrations team to the broader engineering org by participating in architectural design decisions, collaborating with product owners, and providing technical expertise on upcoming product specifications and technical RFCs.
  • Lead by example and help improve engineering processes and workflows within the Integrations space as well in the wider engineering community.
  • Help grow the engineering team by effectively interviewing candidates for various engineering positions.

Team Tech Stack:

  • Python / Django
  • Typescript / React
  • MySQL / Redis / Memcached
  • RabbitMQ / Celery / Apache Kafka / Apache Pulsar
  • Kubernetes
  • AWS

Get to Know Klaviyo

We’re Klaviyo (pronounced clay-vee-oh). We empower creators to own their destiny by making first-party data accessible and actionable like never before. We see limitless potential for the technology we’re developing to nurture personalized experiences in ecommerce and beyond. To reach our goals, we need our own crew of remarkable creators—ambitious and collaborative teammates who stay focused on our north star: delighting our customers. If you’re ready to do the best work of your career, where you’ll be welcomed as your whole self from day one and supported with generous benefits, we hope you’ll join us.

Upon request, you can receive additional information about the compensation and benefits for this role. Requests can be submitted here . Additional information regarding benefits can be found at .

Klaviyo is committed to a policy of equal opportunity and non-discrimination. We do not discriminate on the basis of race, ethnicity, citizenship, national origin, color, religion or religious creed, age, sex (including pregnancy), gender identity, sexual orientation, physical or mental disability, veteran or active military status, marital status, criminal record, genetics, retaliation, sexual harassment or any other characteristic protected by applicable law.

You can find our Job Applicant Privacy Notice here .

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