Principal Engineer-Client Platform

What you will do

• Own and evolve core parts of the Klarna client platform with a strong React Native focus, shaping foundational capabilities used across the app ecosystem.

• Solve complex, cross-cutting technical problems that impact developer experience, stability, scalability, and long-term maintainability of the platform.

• Lead large initiatives spanning JavaScript and TypeScript, frontend build tooling, native iOS and Android integrations, and CI/CD pipelines.

• Balance short-term delivery needs with long-term platform strategy, ensuring solutions are sustainable and aligned with the broader evolution of the Klarna app.

• Act as a technical multiplier by providing mentorship, conducting thoughtful code and architectural reviews, and guiding engineers toward high-quality platform standards.

Who you are

• A React Native and frontend platform expert with strong platform thinking and a hands-on mentality.

• Deeply knowledgeable about React Native internals, including how it builds, runs, and integrates with iOS and Android.

• Highly proficient in JavaScript and TypeScript, with a strong understanding of runtime behavior and architecture patterns.

• Experienced with frontend build systems and tooling, including bundlers, transpilers, Babel, Metro, and Webpack concepts.

• Comfortable debugging complex runtime and build-time issues across the JavaScript to native boundary.

• Proven in evolving React Native at scale, including managing upgrades, shaping architecture, and improving tooling.

• Solid in basic AWS fundamentals such as compute, IAM, networking, monitoring, and database basics.

• Familiar with CI/CD pipelines and modern delivery practices.

• Knowledgeable in security and privacy fundamentals.

• Comfortable working with Node.js, Express, and database fundamentals.

Awesome to have

• Principal-level problem-solving capability without requiring deep native-specialist expertise.

• Comfortable owning ambiguous, high-impact problems and driving them to resolution.

• Thinks in platforms rather than features, with a systems-oriented mindset.

• Pragmatic and delivery-focused, while remaining opinionated about long-term quality and architectural integrity.

• Actively mentors others, raises the technical bar across teams, and contributes as a collaborative, high-trust team player.