Lead Software Engineer - Amplify C.S

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 klaviyo.com/careers to see how we empower creators to own their own destiny.

**Team Overview:**The Amplify Engineering team builds internal tools, platforms, and AI-powered automation that help Klaviyos work more efficiently and at scale as the company grows. We partner across the organisation, including Sales, Marketing, Engineering & Product, Customer Service & Success, and Finance, to solve real operational problems with practical, well-designed software.

Our work spans internal applications, 3rd-party integrations, interactive dashboards, CMS integrations, and robust AI systems and agents that automate repetitive tasks, surface the right information at the right time, and help teams make better decisions. We operate in tight feedback loops with our internal customers, shipping quickly, learning fast, and seeing the impact of our work immediately in how deals move faster, tickets resolve sooner, and launches go more smoothly.

This role is for lead engineers who enjoy turning real-world problems into reliable, scalable solutions. The work is highly visible and has a direct impact on how thousands of Klaviyos get their work done every day.

How You’ll Make an Impact:

The Amplify team builds the internal platforms, automation, and AI-driven systems that power how Klaviyos work every day. As a Lead Software Engineer on Amplify, you will:

• Provide technical oversight and direction for a portfolio of Amplify systems, including internal web applications, APIs, data and event pipelines, and AI-powered workflows used daily by Sales, Marketing, Customer Service & Success, R&D, and Finance teams. You will help ensure they are reliable, scalable, secure, and straightforward to evolve.
• Formulate and drive a forward-looking technical vision for key Amplify domains in partnership with your Engineering Manager, Product, Data, and cross-functional stakeholders, aligning that vision with our AI-first strategy and the business outcomes we are accountable for.
• Lead the end to end lifecycle of complex, multi component projects and platforms that span multiple internal customers and engineering teams, from discovery and technical design through implementation, rollout, and long term ownership.
• Act as the primary technical interface between your areas of ownership in Amplify and the rest of engineering, helping clarify requirements, reduce technical ambiguity and risk, and ensure the team delivers roadmap and OKR commitments on time with the right quality bar.
• Take responsibility for the technical and architectural evolution of multiple significant domains within Amplify, anticipating scalability, reliability, security, and observability needs as usage grows and new use cases emerge.
• Define, refine, and uphold operational standards for the systems you and your team own, including SLOs, monitoring and alerting, incident response practices, and post incident learning that continually improves our operational excellence.
• Create, teach, and improve shared engineering processes, patterns, and internal platforms that make it easier for Amplify and other teams across Klaviyo to build high quality internal tools and AI-powered systems consistently.
• Use modern AI tools as part of your day-to-day engineering workflow and help the team adopt AI effectively, from design and coding through testing, documentation, and evaluation. You will help establish sensible guardrails, evaluation practices, and patterns for AI-first development.
• Work through influence and delegation to get work done, setting clear technical direction, breaking down projects into actionable workstreams, and enabling other engineers to deliver successfully.
• Mentor and coach other engineers across levels through design reviews, pairing, and thoughtful feedback. You will help grow future technical leaders, raise the technical bar for the team, and ensure knowledge is shared rather than concentrated.
• Collaborate closely with Product, Design, Data, and operational partners to define problems, shape trade offs, and agree on success metrics, ensuring Amplify’s work focuses on the highest value opportunities and that outcomes are clearly measured.
• Represent Amplify’s systems and strategy in broader engineering forums, contributing to architectural discussions, technical RFCs, and cross team initiatives, and helping ensure our internal platforms fit well into the wider Klaviyo ecosystem.

Who You Are:

• You care deeply about building software and platforms for the long term, balancing technical quality, delivery pace, and measurable business impact, and you are comfortable making and explaining trade offs at that intersection.
• You have strong hands on experience building and operating highly available, full stack or backend focused SaaS systems, and have been responsible for the health and evolution of multiple services or product areas, not just a single application.
• You have led delivery of business critical projects that span multiple engineers and months, including discovery, technical design, implementation, rollout, and ongoing maintenance. You are comfortable scrutinising requirements, reducing ambiguity, and setting technical direction for others.
• You have deep expertise in several areas of modern web engineering such as backend services, data pipelines, internal platforms, or AI enabled systems, and a strong understanding of scalable, multi-tenant architectures and the operational realities of running them in production.
• You regularly use AI powered tools in your development workflow and are interested in shaping how a team or organisation uses AI thoughtfully to improve engineering productivity, system capabilities, and internal customer experiences.
• You take ownership of operational excellence for the systems you and your team build, including performance, reliability, observability, and on-call participation where required. You are comfortable defining and maintaining SLOs and holding systems to them.
• You are effective at working through influence and delegation. You know when to keep a task for yourself and when to hand it to others, and you enjoy creating the clarity, patterns, and guardrails that let other engineers move quickly and safely.
• You enjoy questioning convention and continuously improving how things work, whether that is architecture, tooling, workflows, or team processes, and you are comfortable introducing change in a way that brings people along with you.
• You are a clear communicator and collaborative teammate, comfortable leading technical discussions, writing design docs or RFCs, and keeping stakeholders aligned from early discovery through delivery and follow up.
• You enjoy working in small, autonomous, agile teams, shipping incrementally, and partnering closely with product managers, data partners, and other engineers to deliver better outcomes for internal customers.

Nice to Have:

• Experience building internal tools, platforms, or automations for developers and or non technical stakeholders, with a track record of improving reliability, productivity, or operational efficiency across multiple teams.
• Experience providing technical leadership across several related systems or domains, including defining technical vision, setting design patterns, and aligning multiple teams on shared approaches.
• Practical experience building or integrating AI powered systems and agents such as workflows using LLM APIs or SDKs, agentic or automated workflows, retrieval augmented generation pipelines, or evaluation and monitoring frameworks for AI systems.
• Experience working with cloud infrastructure (AWS preferred), infrastructure as code (Terraform), and containerised environments (Kubernetes), and designing services that run reliably at scale in those environments.
• Experience partnering closely with customer service & support, go to market, or operations teams to understand complex workflows and build internal tools that drive measurable efficiency gains.

Technologies We Use:

Klaviyo’s platform is primarily built with Python and React and runs on AWS. Engineers join us from a wide range of technical backgrounds and are supported in learning our stack. Core technologies include:

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

Location & Work Model

This role is based in Dublin, Ireland and follows a hybrid working model. Klaviyo supports work authorization and relocation for this position.

At Klaviyo, we enjoy tackling meaningful engineering challenges and value people who take ownership, learn continuously, and collaborate openly. We are committed to building inclusive teams and encourage applications from candidates of all backgrounds.

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.tech

We use Covey as part of our hiring and / or promotional process. For jobs or candidates in NYC, certain features may qualify it as an AEDT. As part of the evaluation process we provide Covey with job requirements and candidate submitted applications. We began using Covey Scout for Inbound on April 3, 2025.

Please see the independent bias audit report covering our use of Covey here

#indeedDUB

Our salary range reflects the cost of labour in the country where the job post is advertised. 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. 

Your recruiter can provide more details about the specific salary/OTE  range for your preferred location during the hiring process.

Base Pay Range in Local Currency:

€112.000—€168.000 EUR

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.

AI fluency at Klaviyo includes responsible use of AI (including privacy, security, bias awareness, and human-in-the-loop). We provide accommodations as needed. 

_By participating in Klaviyo’s interview process, you acknowledge that you have read, understood, and will adhere to our Guidelines for using AI in the Klaviyo interview Process. For more information about how we process your personal data, see our Job Applicant Privacy Notice._

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.

IMPORTANT NOTICE: Our company takes the security and privacy of job applicants very seriously. We will never ask for payment, bank details, or personal financial information as part of the application process. All our legitimate job postings can be found on our official career site. Please be cautious of job offers that come from non-company email addresses (@klaviyo.com), instant messaging platforms, or unsolicited calls.

By clicking "Submit Application" you consent to Klaviyo processing your Personal Data in accordance with our Job Applicant Privacy Notice.  If you do not wish for Klaviyo to process your Personal Data, please do not submit an application.  You can find our Job Applicant Privacy Notice here and here (FR).