Overview 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. How You’ll Make An Impact The Infrastructure Security team builds the internal platforms, systems, and services that serve as the foundational building blocks for how our engineers build securely every day. As a Senior Software Engineer on Infrastructure Security, you will: Ship foundational security services to enable Klaviyo engineering to move faster with confidence Design and develop systems and processes that enable highly available & scalable systems Design, build and deliver software to dramatically improve the availability, scalability, latency, and efficiency of Klaviyo’s services Achieve break-throughs in systems throughput by identifying and eliminating bottlenecks Leverage technology such as Python, Golang, AWS, Django, Kubernetes, Bash, Terraform, MySQL, Redis, Clickhouse, Iceberg, DataLake, Istio, Postgresql, and more to advance Klaviyo’s platform Champion best practices by actively collaborating with other teams in a culture that values whiteboarding and technical design review Contribute to the company as a subject matter expert in multiple areas, constantly pushing yourself to be a better engineer and to level up all of your peers within your team and within Klaviyo Mentor and pair with other Klaviyo engineers to build better software by focusing on performance, self-healing system, configuration as code; defensive programming, application security, etc. Participate in periodic on call duties with a focus on solving issues when they are discovered, preventing recurrences and minimizing alert fatigue Prototype and advocate for architectural improvements to achieve breakthrough results in Klaviyo systems’ operational scalability and reliability Work hand-in-hand with product-facing engineers to ship impactful code Perform quantitative investigation to understand and scale Klaviyo systems and manage the cross-functional effort to resolve scalability issues Produce and advocate for preventative, upstream solutions with internal stakeholders and external vendors and dependencies Confidently make informed, data-driven choices in a fast paced environment with competing priorities 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 with Linux operating systems and computer networking You’re comfortable and experienced writing code in a programming language such as Python, Ruby, Go, etc You have deep experience with cloud infrastructure, operating in a high scale environment You have strong hands-on experience building and operating highly available 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 security tooling, working with security infrastructure systems like Vault, AWS IAM, WAFs, and more Hands-on experience including diagnosing and improving systems performance, database queries, and complex, multi-service workflows Tech Stack Klaviyo’s platform is primarily built with Python and React and runs on AWS. Core technologies include: Python / Django / FastAPI 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. 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. Important privacy and equal opportunity notices are provided as part of the application process. For more details about data privacy, equal opportunity, and compliance, please refer to our Job Applicant Privacy Notice. #J-18808-Ljbffr
A leading technology company based in Dublin is seeking a Senior Software Engineer for its Infrastructure Security team. In this role, you will design and develop foundational security services, mentor other engineers, and ensure the availability and scalability of systems. Ideal candidates have strong expertise in cloud infrastructure, hands-on coding experience, and a commitment to operational excellence. The position offers a hybrid work model and a competitive salary range of €92,000—€138,000. #J-18808-Ljbffr
A leading technology company in Dublin is seeking a Senior Software Engineer to build impactful internal tools and AI-driven systems. This role involves designing, implementing, and maintaining platforms that enhance team efficiency. Candidates should have strong expertise in full-stack SaaS development and a collaborative approach to problem-solving. A hybrid work model is supported, and the salary range is €92,000 to €138,000 EUR, including possible bonuses and equity. #J-18808-Ljbffr
Overview At Klaviyo, we value the unique backgrounds, experiences and perspectives each Klaviyo (we call ourselves Klaviyos) brings to our workplace. We believe everyone deserves a fair shot at success and appreciate experiences beyond traditional job requirements. This role is for a Senior Software Engineer on Amplify, focused on building internal tools, platforms, and AI-powered automation that help Klaviyos work more efficiently and at scale. The work is highly visible and has a direct impact on how thousands of Klaviyos get their work done every day. 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 Sales, Marketing, Engineering & Product, Customer Service & Success, and Finance to solve real operational problems with practical software. Our work spans internal applications, 3rd-party integrations, dashboards, CMS integrations, and robust AI systems that surface the right information at the right time to help teams make better decisions. Location: Dublin, Ireland; hybrid model. Klaviyo supports work authorization and relocation for this position. How You’ll Make An Impact 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. Core technologies include: Python / Django / FastAPI Typescript / React MySQL / Redis / Memcached RabbitMQ / Celery / Apache Kafka / Apache Pulsar AWS / Terraform / Kubernetes Requirements & 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 value ownership, continuous learning, and collaboration. We are committed to building inclusive teams and encourage applications from candidates of all backgrounds. We are growing fast and have openings for all skill levels across all teams. Learn more about our engineering culture at https://klaviyo.tech. Salary: Base pay range in local currency: €92,000—€138,000 EUR. Our total compensation may include bonuses, equity, and benefits; details provided during hiring. AI fluency at Klaviyo includes responsible use of AI. We provide accommodations as needed. By participating in Klaviyo’s interview process, you acknowledge you have read and will adhere to our Guidelines for using AI in the Klaviyo interview Process. Equal opportunity: Klaviyo is committed to a policy of equal opportunity and non-discrimination. #J-18808-Ljbffr
