Expo’s engineering-first philosophy and transparent roadmap align closely with Mollie’s values.

In 2019, the story of Mollie and Expo began not in a boardroom, but in a bar in Amsterdam. Vernon de Goede, Director of Engineering at Mollie, met Cedric van Putten from Expo for a few drinks. "By the end of the afternoon, I was convinced that Expo was the right platform for Mollie," Vernon said. That same weekend, he built the first version of Mollie's mobile app using Expo.

Six years later, the results speak for themselves: a thriving, secure, and resilient mobile app used by tens of thousands of customers every day, with over 250,000 users.

Mollie needed to build a mobile app that could scale quickly across platforms, with a team that had little to no native mobile experience. Expo offered exactly what they were looking for:

• Speed of delivery: a small mobile team rapidly delivered a customer-ready mobile app within weeks
• Stability: Mollie's Expo-powered app is now more resilient than many native counterparts, with bug fixes deployed instantly without waiting for store reviews
• Developer experience: with Expo's transparent engineering culture and excellent documentation, engineers onboarded quickly and focused on shipping value
• Trusted relationship: since 2019, Expo has maintained a direct Slack channel with the Mollie team for enterprise support

At Mollie, everyone is a full-stack engineer. Out of 350 engineers, only about 10 had prior React Native experience. The rest don't even realize they're using React Native. They are simply building features using a cross-platform component library (Mollie UI) that abstracts away the mobile-specific details.

The architecture makes this possible:

• A shared monorepo containing all feature code
• A core team of 5 engineers maintaining both mobile and web platforms
• A modern release process that reduces the gap between mobile and web deployments
• Feature teams free to focus on business logic, without worrying about mobile-specific tooling

Over time, some engineers upskilled themselves to build custom Expo modules, enabling advanced features like Apple Tap to Pay, used by tens of thousands daily to send and receive payments.

Mollie doesn't just build apps. They build hardware too. Their terminal device (Tap) runs an Android app also built with Expo. This approach ensures consistency across all customer touchpoints, from mobile apps to physical terminals.

"A feature can be built once and deployed to iOS, Android, and web with just about 15% overhead," Vernon said. Going fully native would increase that to 300% and require hiring specialists.

• Cross-platform velocity: build once, deploy to iOS, Android, and web
• Rapid iteration: ship fixes and improvements with OTA updates, reducing operational risk
• Engineering alignment: Expo's engineering-first philosophy and transparent roadmap align closely with Mollie's values
• Scalability: with EAS Build and Expo's tooling, hundreds of engineers can contribute seamlessly to the app regardless of mobile expertise

Mollie is redefining what is possible with React Native and Expo. What started as a fast-moving MVP is now a critical product used by over 250,000 customers to send and receive money securely.