We Migrated a KMP App to Compose Multiplatform. Here’s What We Learned 🤔

For the first time, our Android team took on a migration from Kotlin Multiplatform to Compose Multiplatform. The app already shared business logic between Android and iOS through KMP, while each platform had its own UI. With Compose Multiplatform, we wanted to share the UI as well. On paper, it looked straightforward. Our Android UI was already written in Compose, and we’d built most of the app ourselves, so we knew the codebase well. How hard could moving that UI into the shared module be? At one point, we had more than 10,000 compile errors. 😅 Android-specific APIs, incompatible libraries, and native iOS integrations made the migration more involved than we expected. In the video, we walk through what happened, where Claude Code helped, and what we’d do differently if we started again. Watch the full story below. Enjoy! --- Timeline: 00:00 Our First KMP to CMP Migration 01:05 Moving Shared Code and ViewModels 03:12 Fixing 10,000 Compile Errors 04:14 Platform-Specific Code and iOS Challenges 06:17 How Claude Code Helped 07:16 Firebase and iOS Dependencies 08:19 What We’d Do Differently --- Follow Aleksa on LinkedIn: Aleksa Simic -   / aleksa-simic-10bba5182   Stay connected with us: Web → https://www.aetherius-solutions.com LinkedIn →   / aetherius-solutions   Instagram →   / aetherius_solutions   X (Twitter) → https://x.com/AetheriusTech Reddit →   / aetherius_tech   --- Aetherius is a mobile development company powered by a team of experienced engineers with more than 75 successfully delivered projects in different industries. Whether you need native apps for iOS/Android or cross-platform apps written in Kotlin Multiplatform (KMP), Compose Multiplatform (CMP), Flutter, or React Native, our developers deliver them with stability. We offer flexible collaboration models: team augmentation, outsourced team, part-time support, and sprint-based. So, when you need trusted developers to jump into a project, you can always reach out to us!