Kotlin Multiplatform is no longer “experimental curiosity” — it’s a serious choice for production apps.
Companies like Netflix, Cash App, and McDonald's are already using it to share business logic across platforms while keeping native UI experiences intact (LevnTech).
In this post, I’ll walk through how I built a production-ready Kotlin Multiplatform SDK that works seamlessly across Android and iOS — along with the real challenges, trade-offs, and lessons learned.
🤔 Why Kotlin Multiplatform?
Unlike Flutter or React Native, Kotlin Multiplatform doesn’t try to replace native development.
Instead, it lets you:
- Share business logic (networking, caching, models)
- Keep native UI (Jetpack Compose / SwiftUI)
- Avoid code duplication
- Maintain near-native performance
This approach is powerful because you’re not forced into an “all-or-nothing” architecture — you can adopt it gradually (InfoQ).
🧱 Project Architecture
A typical KMP setup looks like this:
- Android App → Uses shared module
- iOS App → Consumes Kotlin framework
- Shared Module → Business logic
Kotlin compiles your shared code into:
- A native framework for iOS
- A standard module for Android
This means no bridges, no JavaScript layer — just native performance (DEV Community).
🚀 What I Built
The goal was simple:
👉 Create a production-grade SDK that:
- Can be reused across apps
- Is easy to integrate
- Handles real-world concerns (networking, error handling, scalability)
⚙️ Key Challenges (and How I Solved Them)
1. API Design for Two Worlds
Designing an SDK that feels “native” on both Android and iOS is harder than it sounds.
Solution:
- Keep APIs minimal and platform-agnostic
- Use expect/actual wisely
- Avoid leaking platform-specific abstractions
2. Dependency Management
Not all libraries are multiplatform-ready.
Solution:
- Prefer KMP-compatible libraries (e.g., Ktor)
- Abstract dependencies behind interfaces
3. iOS Interoperability
Swift + Kotlin interop can get tricky.
Solution:
- Design Swift-friendly APIs
- Avoid overly complex generics
- Test from Xcode early, not later
4. Build & CI Complexity
KMP builds can become slow and complex.
Solution:
- Optimize Gradle configuration
- Separate concerns into modules
- Cache aggressively in CI
🧪 Production Learnings
After taking this setup closer to production, a few things stood out:
- You can realistically share 70–80% of business logic
- Debugging is manageable with standard tools
- The biggest gains come from team alignment, not just code reuse
📦 When Should You Use KMP?
Kotlin Multiplatform is a great fit if:
✅ You have both Android and iOS apps
✅ Your business logic is complex and shared
✅ You want native UI but shared architecture
Avoid it if:
❌ Your app is UI-heavy with little shared logic
❌ Your team lacks Kotlin experience
💡 Final Thoughts
Kotlin Multiplatform hits a sweet spot:
- Not a full abstraction layer
- Not fully separate codebases
It gives you shared logic where it matters, without sacrificing native quality.
If you're building something meant to scale across platforms, it’s absolutely worth considering.
🔗 Full Article
If you want the complete deep dive with implementation details, check it out here:
🙌 Feedback
If you're working with Kotlin Multiplatform or planning to, I’d love to hear your experience.
What’s been your biggest challenge so far?
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