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 careers.klaviyo.com 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 senior 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 Senior Software Engineer on Amplify, you will:

Design, build, and own complex internal products and platforms, 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.
Lead the end-to-end lifecycle of projects and features – from discovery and technical design through implementation, rollout, and long-term ownership.
Partner closely with internal customers to understand their workflows and constraints, and translate real operational challenges into scalable, maintainable solutions that measurably improve productivity, quality, and reliability.
Take ownership of the technical and architectural evolution of parts of the Amplify platform, anticipating scalability, reliability, and observability needs as usage grows.
Define and maintain operational standards for the systems you own, including SLOs, monitoring, incident response, and follow-up on root-cause analysis.
Use modern AI tools as part of your day-to-day engineering workflow (e.g. LLM-based tooling for design, coding, testing, and documentation), and help shape best practices for how the team applies AI responsibly and effectively.
Contribute to shared patterns, tooling, and processes that make it easier for teams across Klaviyo to build high-quality internal tools and AI-powered systems consistently.
Mentor and support other engineers through design reviews, pairing, and constructive feedback, leaving the codebase and systems better than you found them.
Collaborate closely with Product, Design, Data, and operational partners to define requirements, trade-offs, and success metrics, ensuring Amplify’s work focuses on the highest-value problems.

Who You Are:

You care deeply about building software for the long term, balancing technical quality, delivery pace, and business impact.
You have strong hands-on experience building and operating highly available, full-stack SaaS systems, and are comfortable owning complex problems end to end.
You’ve led the delivery of significant projects or features independently, including discovery, technical design, implementation, rollout, and ongoing maintenance, and you’re comfortable providing technical direction to others.
You have deep expertise in one or more areas of modern web engineering (e.g. backend services, data pipelines, internal platforms, or AI-enabled systems) and a solid understanding of scalable, multi-tenant architectures.
You regularly use AI-powered tools in your development workflow and are curious about applying AI thoughtfully to improve engineering productivity and system capabilities.
You take ownership of operational excellence for the systems you build, including performance, reliability, observability, and on-call participation where required.
You enjoy questioning convention and continuously improving how things work, whether that’s architecture, tooling, workflows, or team practices.
You are a clear communicator and collaborative teammate, comfortable leading technical discussions, writing design docs or RFCs, and keeping stakeholders aligned.
You enjoy working in small, autonomous, agile teams, shipping incrementally, and partnering closely with product managers and other engineers to deliver better outcomes.

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.
Hands-on experience in full-stack environments, including diagnosing and improving application performance, database queries, and complex, multi-service workflows.
Practical experience building or integrating AI-powered systems and agents; e.g., workflows using LLM APIs/SDKs, agentic or automated workflows, RAG pipelines, or evaluation/monitoring frameworks.
Experience working with cloud infrastructure (AWS preferred), infrastructure-as-code (Terraform), and containerised environments (Kubernetes), and designing services that run reliably at scale.

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

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:

€92.000—€138.000 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).

Senior Software Engineer - Amplify C.S

Benefits

Job Description