Software Engineer, Internationalisation Platform (Hiring Immediately) in London

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.

Why You Should Join the Internationalisation Platform Team

The i18n Platform team owns all the ways we create, process and deliver internationalisation features for our users at Klaviyo. As a Software Engineer on the team, you will be involved in how we manage translations, deliver new localisation features, handle multiple currencies, and improve our internationalisation processes.

You can look forward to being a part of a highly technical team with significant domain expertise. We oversee tools and services that are leveraged across the organization from the frontend UI to backend data. The team also owns and orchestrates several services to manage the pipeline of translations with our localisation team.

As we look toward the next 6-12 months, we aim to focus on delivering LLM workflows to improve our translation capabilities, increase the availability of our Smart Translations product, and develop new features for handling different currencies in multiple regions.

Why you should join

• We foster a culture of psychological safety, collaboration, and work/life balance through flexible hours and structured on-call rotations.
• We practice a “you make it, you support it” attitude to our products and provide on-call support in case of incidents.
• We offer compensation for on-call rotations and expect to maintain a very low number of incidents requiring call-out.
• New engineers are onboarded to the on-call rotation gradually, typically joining the active rotation after their first 6 months and thorough training.
• We are committed to your growth. You will be paired with a dedicated mentor and given time for focused skill development, including opportunities to attend relevant industry conferences and a growing suite of learning & development opportunities.
• We enjoy a high degree of autonomy to generate innovative solutions across the entire system, learning directly from customers and suggesting cool new approaches.
• Free lunch at our Aldgate office three times a week.
• Highly competitive salary, equity package, and comprehensive health benefits.

How You Will Make a Difference

• You will collaborate closely with the team to build the next generation of i18n features for our customers and fellow engineers.
• You will be responsible for implementing new functionality into complex systems.
• You will work closely with engineers from other teams across Klaviyo to bring internationalisation processes and features to their code.
• You will be an active participant in all team processes including standups, backlog refinement, retrospectives, on call, and more.
• You will help interview new engineering team members as we continue to grow our organization.
• You will own and deliver features end-to-end, learning to scope and execute small-to-medium-sized projects under the guidance of your mentor.

What we are looking for

• A strong interest in internationalisation, localisation, and translation.
• A desire to serve our international customers and expand Klaviyo’s capabilities.
• 2-5 years of experience in a software engineering discipline (We are keen to support growth for candidates at the lower end of this range).
• Familiarity with full stack development concepts and a strong aptitude to learn.
• Experience working with both monolithic and microservices architectures.
• Experience with database design that can withstand high query volumes.
• Experience with CI/CD pipelines.
• Experience debugging performance issues and improving application performance.
• An interest and aptitude for collaboration across teams and disciplines.
• An understanding of challenges in developing software across multiple languages and catering to non-English speaking users.
• Thrives in a fast paced, customer focused, and strategic environment.

Nice to Have

• Experience creating new services with scalability in mind.
• Exposure to large-scale system design.
• Experience with AWS or any similar cloud provider.
• Experience with billing systems in multiple currencies.

Technologies we use (not exhaustive):

• React, TypeScript, JavaScript, HTML, CSS.
• Babel, Webpack, Eslint, Prettier.
• REST, GraphQL, JSON Schema, JSON:API.
• CDNs (Fastly, Cloudflare), GitHub, BuildKite.
• MySQL, Redis, Pulsar, Memcache.
• Python, Django, FastAPI, Go, Gin, React, RabbitMQ, Celery, MySQL, DynamoDB, Cassandra, Redis.
• DeepL, Smartling, Stripe.
• Amazon Web Services (EC2, RDS, Aurora, AWS Translate, etc.), Terraform, Kubernetes, Splunk, Chronosphere, Cortex, DX, and other modern DevOps tools.
• Bedrock, Claude, Cursor, LangChain, OpenAI, Gemini.

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.