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Klarna App

Started in January 1, 2021 (over 3 years ago)

During my two years at Klarna, I had the chance to work extensively on the Klarna App. It's a Super-app that serves as a Banking app, Payment app, Shopping app, and Wishlist app. I worked on the Klarna Card feature in the app. It is a monorepo using both React and React Native and contains hundred of thousands of lines of code, with hundreds to thousands of engineers working on it daily.

I was part of the team that implemented and maintained several critical features in the last years:

  • Released the Virtual Card, a companion credit card to the Klarna Card. Available in several markets in Europe. More than 100 000 Virtual Cards were created within the first year.
  • Released the "See Card Details" feature that allows users to see their PAN, CVV, and Expiry Date for all their cards. Used daily by thousands of users.
  • Released the Card Home screen that displays all users' Klarna branded cards. Also released a framework allowing other teams to easily add their components to the screen based on the card type.
  • Maintained Apple Pay & Google Pay integration.  Around 50% of Klarna Card users have the cards on at least one wallet provider.
Klarna overview


Most of the challenges came from the high number of users and markets each change in the app impacts. Our products were available in several markets and therefore required to be flexible and scalable enough to adapt to each market's specificity. We had services running on AWS in several regions (Europe, Northern America, Asia-Pacifique). If you want to learn more about Klarna's cloud strategy, watch this talk at Dash 2021.

Key Achievements:

  • Migrated 100% of the team’s existing codebase to TypeScript.
  • Worked in close collaboration with the designers to improve the app over time. With a strong focus on using animations to enhance UX and accessibility to be more inclusive.
  • Implemented and used A/B testing, feature flags, monitoring tools, analytics... all that fancy stuff.
  • Gave a talk at Klarna’s KonferenSE20 about animations and micro-interactions.
  • Hosted numerous domain-wide presentations to demo key achievements or present technical solutions to stakeholders and other engineers in the Card domain.