Senior Software Engineer Amplify C.S

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 Youll 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 Amplifys 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.
• Youve led the delivery of significant projects or features independently including discovery technical design implementation rollout and ongoing maintenance and youre 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 thats 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:

Klaviyos 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

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

Required Experience:

Senior IC