Hi, I'm Perttu Lähteenlahti — a developer and designer based in Finland. I've spent the last decade designing and building digital products, from mobile apps to web platforms. I also won 40+ hackathons along the way.
Currently, I work as a Senior Developer Advocate at RevenueCat, where I help developers build and monetize their apps. My focus is on React Native, cross-platform development, and making in-app purchases less painful. You can read more about me, or see what I'm up to now.
I write practical, production-focused guides about React Native, iOS and Android development, mobile performance, and app monetization — especially subscriptions and in-app purchases. Most articles are based on real issues I've hit while building and shipping apps in production.
I write about React Native development, mobile app monetization, in-app purchases, and lessons learned from building products. Here are some of my recent posts.
Use Linking.canOpenURL to detect if another app is installed on iOS in Expo. Covers Expo config plugin setup, URL scheme configuration, CNG workflow, and a hook to conditionally show a deep link button.
ASC CLI lets you skip App Store Connect's clunky web UI and manage builds submissions, and localizations from your terminal. Pair it with AI skills and it gets even better.
A hackers guide to building an MVP that can win RevenueCat's Shipyard hackathon
Overengineered approach to tracking how many books I've read in 2026, with filtering, auto generated images, and progress bars
How to make money with your Flutter app
FlutterKaigi 2025
Building & monetizing a React Native app for three platforms in 20 minutes
React Advanced London 2025
Why React Native apps make all the money
React Conf 2025
