Klarna

The Challenge

As Klarna's mobile app grew to millions of daily active users, maintaining performance and scalability became critical. The organization needed robust tooling to measure real-world app performance and infrastructure to handle massive scale marketing data.

App Performance Tooling

I joined the dedicated App Performance Team to build and refine tooling that tracks performance metrics across the React Native and native (iOS/Android) layers.

• Developed a custom performance dashboard using React/Next.js and Node.js to visualize trends and regressions.
• Implemented benchmarking for React Native TypeScript code vs Native modules to identify bottlenecks.
• Acted as an advisor to other product teams, helping them optimize their feature implementations.

Marketing Tech & Infrastructure

Later, moving to the Media Foundation & Ad Tech team, I took on the Engineering Manager / Competence Lead role. We were responsible for the tracking and analysis of marketing campaign performance.

• Integrated third-party tracking software securely into the main app.
• Built data ingestion pipelines using AWS SQS, Lambda, and Redshift to process campaign data.
• Developed an internal web application (T3 stack) for generating and managing campaign links.
• Built an AI marketing assistant using OpenAI APIs to query historical campaign data and suggest strategies.

Impact

The tooling we built provided visibility that allowed the app to remain performant while adding significant new features. The marketing infrastructure enabled data-driven decision making for campaigns reaching millions of customers globally.