You are passionate about building software effectively and for the long-term.  You have 4+ years of hands-on software development experience creating and maintaining highly available, full-stack SaaS products at scale. Bachelor’s degree or equivalent. A good understanding of the Integrations technical space - 3rd party APIs, authentication, storage, and data pipelines. You have an in-depth understanding of commonly used web architecture design patterns when it comes to highly scalable systems.  You have been a successful interface between the team and the rest of your product area. You have been responsible for owning and delivering projects or features of projects including design, development, and deployment. You possess excellent verbal and written communication skills. Through effective proactive communication and planning, you keep your team up to date on project progress and any blockers or delays. 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 have a good understanding of popular AI tools (ChatGPT, Claude Code, Cursor, Gemini, etc.) and know how to use them effectively in your own day-to-day workflow to increase coding and productivity efficiency. You enjoy working with new technologies ranging from the frontend to backend, and are particularly passionate and an expert in various tech stacks. Ability to dig into performance and scalability issues to drive breakthrough solutions-- whether it's a slow loading UI or too many clicks in a workflow, a database query timing out, or a queue that just won’t drain. 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. You are proficient in writing technical specifications and documents based on product feature specifications provided by the Product team, and are adept at breaking down and articulating complex technical concepts in a clear and concise manner. You are capable of leading discussions and presentations to ensure alignment on architectural decisions, promoting transparency, and facilitating a shared understanding across teams.  Highly collaborative, ambitious, and ability to champion ideas based on merit. At the same time, being humble enough to recognize your own areas of improvements and open to feedback and continuous learning. You’ve already experimented with AI in work or personal projects, and you’re excited to dive in and learn fast. You’re hungry to responsibly explore new AI tools and workflows, finding ways to make your work smarter and more efficient.

Have an opportunity to make a major impact on the direction and priorities of the Integrations team - wholly owning features that 160,000+ customers rely on daily to reach 4B+ consumers to drive their business forward. Be responsible for the mission, technical direction and operations of projects that have immediate impact. Responsible for building and managing Klaviyo’s integrations, 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. Helping architect and design robust and high performance data processing and storage systems to serve different internal and external use cases. Build prototypes, establishes design patterns, consults with domain experts and otherwise wors to ensure a team's successful delivery of technical solutions. Contribute to the Klaviyo R&D team as a subject matter expert in multiple areas. Provide quality PR reviews for our code-owned areas of the application. Lead by example and help improve engineering processes and workflows within the Integrations space as well in the wider engineering community.   Tech Stack: Klaviyo operates a real-time data analytics platform coded primarily in Python that is built for massive scale and hosted on Amazon Web Services (AWS). New hires come to Klaviyo  from a number of disciplines with experience in a variety of languages and tech stacks. Here is our primary tech stack: Python / Django  Typescript / React MySQL / Redis / Memcached RabbitMQ / Celery / Apache Kafka / Apache Pulsar Kubernetes AWS At Klaviyo, we love tackling tough engineering problems and look for employees who are passionate about building, owning, and scaling features end-to-end and breaking through obstacles or technical challenges in their way. We push each other to move out of our comfort zone, learn new technologies, and work hard to ensure each day is better than the last.  Klaviyo is growing fast and we have openings for all skill levels across all of our teams. Learn more about our engineering culture at https://klaviyo.techMassachusetts Applicants:It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability. Our salary range reflects the cost of labor across various U.S. geographic markets. The range displayed below reflects the minimum and maximum target salaries for the position across all our US locations. The base salary offered for this position is determined by several factors, including the applicant’s job-related skills, relevant experience, education or training, and work location. In addition to base salary, our total compensation package may include participation in the company’s annual cash bonus plan, variable compensation (OTE) for sales and customer success roles, equity, sign-on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility. Please visit Klaviyo Rewards to find out more about our Total Rewards package. Your recruiter can provide more details about the specific salary/OTE range for your preferred location during the hiring process.Base Pay Range For US Locations:$120,000—$180,000 USDGet 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. AI fluency at Klaviyo includes responsible use of AI (including privacy, security, bias awareness, and human-in-the-loop). We provide accommodations as needed.  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.