Team Overview The Infrastructure Security team makes it simple and easy for engineers to make secure choices while developing world class software at high speed. Security is built in by default, seamless, and effortless, making engineers’ lives better and Klaviyo more secure. Our work spans security, infrastructure, and software development, requiring us to understand systems and engineering. We build complex, foundational solutions that must be extremely reliable, secure, and performant at global scale. 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 hundreds of Klaviyos get their work done every day, and 100’s of thousands of customers use our products with confidence. 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. 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 system performance, database queries, and complex, multi‑service workflows. Tech Stack 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 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 #J-18808-Ljbffr
A leading technology company based in Dublin seeks a Senior Software Engineer to join their Infrastructure Security team. In this role, you will design and develop foundational security services, allowing engineers to build securely and efficiently. The role involves mentoring peers, improving system performance, and participating in on-call duties. Ideal candidates should have strong experience with Linux, cloud infrastructure, and security tooling. This position offers a hybrid working model and the opportunity to tackle significant engineering challenges. #J-18808-Ljbffr
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 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 #J-18808-Ljbffr
A leading tech firm in Dublin is searching for a Senior Software Engineer to design and build internal platforms that enhance productivity across teams. This is a hybrid role where you will collaborate with various departments to create scalable solutions. The ideal candidate has extensive experience in full-stack development, especially with Python and React, and is comfortable leading projects. This position offers significant visibility and impact on the company's operations, making it ideal for those passionate about engineering excellence. #J-18808-Ljbffr
