<div class="content-intro">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 <a class="_ymio1r31 _ypr0glyw _zcxs1o36 _mizu194a _1ah3dkaa _ra3xnqa1 _128mdkaa _1cvmnqa1 _4davt94y _4bfu18uv _1hms8stv _ajmmnqa1 _vchhusvi _kqswh2mm _ect4ttxp _syaz13af _1a3b18uv _4fpr8stv _5goinqa1 _f8pj13af _9oik18uv _1bnxglyw _jf4cnqa1 _30l313af _1nrm18uv _c2waglyw _1iohnqa1 _9h8h12zz _10531ra0 _1ien1ra0 _n0fx1ra0 _1vhv17z1" href="http://klaviyo.com/careers" data-renderer-mark="true">klaviyo.com/careers</a> to see how we empower creators to own their own destiny.</div>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: <ul> <li>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.</li> <li>Lead the end-to-end lifecycle of projects and features – from discovery and technical design through implementation, rollout, and long-term ownership.</li> <li>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.</li> <li>Take ownership of the technical and architectural evolution of parts of the Amplify platform, anticipating scalability, reliability, and observability needs as usage grows.</li> <li>Define and maintain operational standards for the systems you own, including SLOs, monitoring, incident response, and follow-up on root-cause analysis.</li> <li>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.</li> <li>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.</li> <li>Mentor and support other engineers through design reviews, pairing, and constructive feedback, leaving the codebase and systems better than you found them.</li> <li>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.</li> </ul> Who You Are: <ul> <li>You care deeply about building software for the long term, balancing technical quality, delivery pace, and business impact.</li> <li>You have strong hands-on experience building and operating highly available, full-stack SaaS systems, and are comfortable owning complex problems end to end.</li> <li>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.</li> <li>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.</li> <li>You regularly use AI-powered tools in your development workflow and are curious about applying AI thoughtfully to improve engineering productivity and system capabilities.</li> <li>You take ownership of operational excellence for the systems you build, including performance, reliability, observability, and on-call participation where required.</li> <li>You enjoy questioning convention and continuously improving how things work, whether that’s architecture, tooling, workflows, or team practices.</li> <li>You are a clear communicator and collaborative teammate, comfortable leading technical discussions, writing design docs or RFCs, and keeping stakeholders aligned.</li> <li>You enjoy working in small, autonomous, agile teams, shipping incrementally, and partnering closely with product managers and other engineers to deliver better outcomes.</li> </ul> Nice to have: <ul> <li>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.</li> <li>Hands-on experience in full-stack environments, including diagnosing and improving application performance, database queries, and complex, multi-service workflows.</li> <li>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.</li> <li>Experience working with cloud infrastructure (AWS preferred), infrastructure-as-code (Terraform), and containerised environments (Kubernetes), and designing services that run reliably at scale.</li> </ul> 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: <ul> <li>Python / Django / FastAPI</li> <li>Typescript / React</li> <li>MySQL / Redis / Memcached</li> <li>RabbitMQ / Celery / Apache Kafka / Apache Pulsar</li> <li>AWS / Terraform / Kubernetes</li> </ul> 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 <a href="https://getcovey.com/product/covey-scout-inbound">Covey Scout for Inbound</a> on April 3, 2025.Please see the independent bias audit report covering our use of Covey <a href="https://getcovey.com/nyc-local-law-144" style="text-decoration:underline">here</a><div class="content-pay-transparency"><div class="pay-input"><div class="description">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 sala

Senior Software Engineer - Amplify C.S