// Mobility · Travel
Europcar Mobility App
Led iOS architecture in the founding team of Europcar's mobility app at Martian & Machine, a SwiftUI app on a Kotlin Multiplatform core, doubling development speed and raising test coverage by 75%.
- SwiftUI on a shared Kotlin Multiplatform core
- 2× development speed from the founding architecture
- +75% code coverage, two-thirds fewer bugs in testing
The product
The Europcar Mobility App is Europcar’s all-in-one app for getting around. It brings together several services that used to live apart:
- Car rental worldwide, with real-time availability
- Car-sharing across Germany for short trips
- E-scooters and e-bikes in 18 countries
- Bookings, payments and profile in one place, with 24/7 support
Kotlin Multiplatform at the core
Kotlin Multiplatform (KMP) was central to the stack. The iOS and Android apps share Kotlin code, and the shared side uses Decompose for components and navigation. On iOS, the UI is native SwiftUI built on top of that shared core, so both platforms get one implementation of the logic and a fully native experience.
The iOS work covered the app’s key features, including maps, payments and unlocking vehicles from the phone.
What I did
I joined Martian & Machine’s founding team for the app as a Senior iOS Engineer.
- Founding architecture. I led the iOS architectural design within the founding team, which doubled development speed and feature delivery, and kept the engineers working smoothly together.
- Modularization. I made the architectural decisions that split features into isolated, composable modules, keeping the codebase scalable as the product grew.
- Testing. I introduced unit testing practices that raised code coverage by at least 75%.
- Standards. I wrote the coding standards the team worked to, keeping the code consistent and technical debt to a minimum.
- Mentoring. I ran training sessions and set clear guidelines for junior developers. Bugs reported during testing dropped by over two-thirds.